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17097 


THE  UNIVERSITY  OF  CHICAGO 
NATURE-STUDY  SERIES 

Editor 
ELLIOT  R.  DOWNING 


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A  NATURALIST  IN  THE  GREAT 
LAKES  REGION 


THE  UNIVERSITY  OF  CHICAGO  PRESS 
CHICAGO.  ILLINOIS 


THE  BAKER  &  TAYLOR  COMPANY 

NEW  YORK 


THE  CAMBRIDGE  UNIVERSITY  PRESS 

LONDON 

THE  MARUZEN-KABUSHIKI-KAISHA 

TOKYO,  OSAKA,  KYOTO,  FUKDOKA,  SEKDAI 

THE  MISSION  BOOK  COMPANY 

SHANGHAI 


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A  NATURALIST 
IN  THE  GREAT 
LAKES    REGION 


By 


ELLIOT  ROWLAND  DOWNING 

The  School  of  Education^  University  oj  Chicago 


M^i 


THE  UNIVERSITY  OF  CHICAGO  PRESS 
CHICAGO,  ILLINOIS 


Copyright  1Q22  By 
The  University  of  Chicago 


All  Rights  Reserved 


Published  April  1922 
Second  Impression  August  1922 


Composed  and  Printed  By 

The  University  of  Chicago  Press 

Chicago,  Illinois,  U.S.A. 


GENERAL  PREFACE 

Never  before  in  this  country  has  there  been  so  insistent  a 
demand  for  a  more  thorough  and  more  comprehensive  system 
of  instruction  in  practical  science.  Forced  by  recent  events  to 
compare  our  education  with  that  of  other  nations,  we  have 
suddenly  become  aware  of  our  negligence  in  this  matter.  Now 
industrial  and  educational  experts  and  commissions  are  united 
in  demanding  a  change. 

While  on  the  whole  there  has  been  a  steady  increase  in  the 
amount  of  time  given  to  science  work  in  the  secondary  and  ele- 
mentary schools,  the  attention  paid  to  it,  especially  in  the 
elementary  schools,  has  been  somewhat  spasmodic,  and  its 
administration  has  been  more  or  less  chaotic.  This  is  not  due 
to  lack  of  interest  on  the  part  of  school  officials  but  to  their 
dissatisfaction  with  the  methods  of  instruction  emplo}'ed. 
There  is  no  doubt  that  superintendents  would  gladly  introduce 
more  science  if  they  felt  sure  that  the  educational  results  would 
be  commensurate  with  the  time  expended.  This  is  indicated 
by  a  recent  survey  of  about  one  hundred  and  fifty  cities  in 
seven  states  of  the  Central  West.  The  survey  shows  that  two- 
thirds  of  them  have  nature-study  in  the  elementary  schools  and 
that  all  are  requiring  some  science  for  graduation  from  the  high 
school.  The  average  high  school  is  offering  three  years  of  science. 
Since  1900  there  has  been  a  greater  increase  in  the  percentage 
of  students  enrolled  in  science  in  the"  high  schools  than  in  an\- 
other  subject  with  the  one  exception  of  EngHsh.  IVIoreover, 
greater  attention  is  now  being  paid  to  the  training  of  teachers 
in  methods  of  presentation  of  science. 

The  chief  needs  in  science  instruction  toda>'  are  a  niDre 
efficient  organization  of  the  course  of  study  with  a  \icw  to  its 
socialization  and  practical  appKcation,  and  a  clear-cut  realiza- 


»^. 


vu 


Viii  GENERAL  PREFACE 

tion  on  the  part  of  the  teacher  of  the  aims,  the  principles  of 
organization,  and  the  methods  of  instruction;  it  is  to  meet  these 
needs  that  this  series  is  being  issued.  The  books  attempt  to 
present  such  generalizations  of  science  as  the  average  pupil 
should  carry  away  from  his  school  experience  and  to  organize 
them  for  the  preparation  of  the  teacher  and  for  presentation  to 
the  class.  The  volumes  will  therefore  be  of  three  kinds: 
(i)  source  books  with  accompanying  field  and  laboratory  guides 
for  the  use  of  students  in  normal  schools  and  schools  of  educa- 
tion, and  of  teachers,  (2)  pupils'  texts  and  notebooks,  and 
(3)  books  on  the  teaching  of  the  various  science  subjects.  In 
the  first  the  material  will  be  organized  with  special  reference 
to  the  training  of  the  teacher  and  the  most  effective  methods 
of  presenting  the  subject  to  students.  In  the  second  the  matter 
will  be  simpHfied,  graded,  and  arranged  in  such  a  way  that 
the  books  will  serve  as  guides  in  science  work  for  the  pupils 
themselves.  Moreover,  they  will  furnish  texts  for  the  grades 
and  high  school  that  will  simpKfy  the  teacher's  task  of  presenta- 
tion and  will  assure  well-tried  and  well-organized  experiences, 
on  the  part  of  the  pupil,  \\dth  natural  objects.  This  series  of 
texts  for  elementary  and  secondar}^  schools  mil  have  dependent 
continuity  and  the  subject-matter  will  gradually  increase  in 
difficulty  to  accord  with  the  increasing  capacity  of  the  pupils. 
It  will  furnish  a  unified  course  in  science.  The  third  t}^e  of 
book  is  for  the  teacher  and  deals  wath  the  history,  aims,  prin- 
ciples of  organization,  and  methods  of  instruction  in  the  several 
sciences. 


AUTHOR'S  PREFACE 

There  is  no  commonplace;  the  most  dully  monotonous 
environment  is  full  of  wonders,  if  vision  can  be  enlarged  to 
apprehend  them.  J.  Henri  Fabre,  that  astute  French  naturalist 
whose  portrayal  of  the  interesting  Hves  of  the  humble  denizens 
of  field  and  forest  we  are  all  reading  with  avidity,  saw  more  of 
the  marvelous  in  his  own  back  yard  than  the  average  globe- 
trotter sees  in  all  his  travels.  Slabsides  was  but  a  poor  shack 
in  an  ordinary  farm  wood  lot.  The  pond  at  Walden  has  its 
dupHcate  in  the  outskirts  of  a  thousand  American  villages. 
But  John  Burroughs  and  Henry  D.  Thoreau  had  eyes  to  see, 
ears  to  hear,  and  hearts  to  understand. 

Fortunately  there  is  an  ever-increasing  number  of  persons, 
both  young  and  old,  who  are  learning  what  fascination  there  is 
in  the  tales  Nature  spreads  before  our  eyes  in  hill  and  dale, 
river  and  forest,  bird  and  beast,  flower  and  blade  of  grass. 
They  are  learning  to  read  the  landscape,  to  achieve  a  companion- 
ship in  the  outdoors  quite  as  real  and  as  satisfying  as  that  of  a 
wise  friend  or  a  stimulating  book.  For  such  this  book  is  written 
as  an  aid  to  an  understanding  of  familiar  surroundings. 

It  is  hoped  the  volume  may  serve  as  an  advanced  general 
science,  particularly  for  those  teachers  who  beheve  that  science 
instruction  at  its  best  is  an  attempt  to  interpret  the  significance 
of  the  commonplace.  It  craves  audience,  too,  of  all  those 
nature-lovers  who  desire  an  introduction  to  the  study  of  the 
things  about  them  as  one  means  of  culture.  The  several  type 
regions  are  treated  in  separate  chapters  so  that  one  ma>'  take  it 
as  a  companion  into  the  Dunes,  the  forest,  the  prairie,  the  river 
valley  and  learn  by  means  of  the  brief  descriptions  and  illustra- 
tions to  identify  the  plants,  animals,  and  physiographic  processes 
encountered,  and  appreciate  something  of  their  .meaning. 

ix 


X  AUTHOR'S  PREFACE 

The  author  is  indebted  to  Miss  Helen  Snyder  for  the  care 
with  which  many  of  the  drawings  have  been  made.  While  the 
drawings,  except  as  acknowledged  in  the  text,  have  been  made 
from  the  specimens,  suggestions  as  to  methods  of  expressing 
essential  characters  have  been  taken  at  times  from  the  books 
mentioned  in  the  Hst  at  the  end  of  the  volume.  The  author 
gratefully  acknowledges  his  indebtedness. 

A  few  of  the  half-tone  illustrations  are  from  negatives  in  the 
collection  of  the  School  of  Education,  for  the  use  of  which  the 
author  expresses  his  indebtedness. 

Elliot  R.  Downing 

University  of  Chicago 

School  of  Education 

December  27,  1921 


CONTENTS 

PAGE 

xiii 

CHAPTER 

I.    The  Changing  Face  of  Nature      ......         i 


List  or  Illustrations 


II.  The  World  in  the  Making 21 

III.  The  Story  of  Our  Rock  Foundation 36 

IV.  The  Glacial  Period 56 

V.  Lake  Chicago  and  Its  Old  Shore  Lines       .       .       .       .  78 

VI.  Distribution  and  Adjustment 90 

VII.  The  Dunes  and  Their  Plants 112 

VIII.  Animals  of  the  Dunes 148 

IX.  Interdunal  Ponds  and  Tamarack  Swamps   .       .       .       .167 

X.    The   Climax   Forest    and    Its    Predecessor,    the    Oak- 
Hickory  Type 202 

XI.  Lake  to  Forest  or  Prairie 232 

XII.  Lake  Bluff,  Ravine,  and  River  Valley      .       .       .       .259 

XIII.  Brook,  Creek,  and  River 276 

XIV.  Some  Sources  of  Our  Fauna  and  Flora      ....     293 

An  Outline   of  Some   of  the  Important  Plant  and  Animal 

Associations 305 

Book  List 308 

Index 3" 


XI 


LIST  OF  ILLUSTRATIONS 


Bold 


Fig. 

Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 

Fig. 
Fig. 

Fig. 
Fig. 
Fig. 
Fig. 
Fig. 

Fig. 
Fig. 
Fig. 

Fig. 
Fig. 
Fig. 


Fig. 
Fig. 


Headlands  on  Lake  Superior Frontispiece 

Chapter  I 


I. — Eroding  Clay  Bluffs  on  the  Shore  of  Lake  Michigan  with 

Vegetation  Sliding  Down  into  Lake  .... 
2. — Serried  Ranks  of  Billows,  Lake  Superior  Shore   . 


lO 

II 

12 

13 
14 

15 
16 

17 
18 

19 


— A  Stream  Cutting  Its  Banks 

— A  Mountain  Torrent  in  Its  Narrow  Valley  . 

— The  Beginnings  of  a  Ravine  near  Glencoe    . 

— A  Deep  V-Shaped  Ravine  near  Fort  Sheridan     . 

— The  Dalles  of  the  Wisconsin  River        .... 

— ^The  Valley  of  the  Illinois  at  Starved  Rock  . 

— ^A  Narrow  Rock  Ravine  Ending  in  a  Waterfall  at  Starved 

Rock 

— The  Glacier,  a  Stream  of  Ice,  Canadian  Rockies 

— Clay  Pinnacles,  Rainwashed,  near  Lakeside,  Michigan — 

Inset,  Near  View  of  Pinnacles    .        .       ... 
— Talus  at  Foot  of  Cliff  and  Outwash  from  the  Hills     . 
— A  Hill  of  Sand  Moving  Inland,  South  End  of  Lake  ^Michigan 

— ^A  Blow-out  in  the  Dunes 

— A  Filling  Pond 

— A  Flood  Plain  Where  Deposits  Occur  Annually,  Salt  Creek 

near  Brookfield 

— Up-Arched  Rock  Strata,  Pennsylvania 

— ^Lava  Outflow  Forming  Great  Areas  of  Rock 

— The  Terminal  IMoraine  of  a  Glacier       .... 

Chapter  II 


PAGE 
2 

3 

4 

5 

5 
6 

7 
8 

9 
Q 

10 
12 

13 
14 

15 

15 
iS 

19 
19 

-M 


20. — Cafion  Diablo 

21. — ^A  Spiral  Nebula 

22. — Diagrammatic  Section  of  the  Earth 26 

Chapter  III 

23. —The  Quarries  of  Stony  Island  Showing  Opposite  Inclina- 
tion of  Strata 37 

24.— Diagram  of  Rock  Strata  Found  in  Deep  Boring  at  Lock- 
port,  Illinois 3'^ 

xiii 


XIV  LIST  OF  ILLUSTRATIONS 


PAGE 


Fig.    25. — ^A  Dyke  near  Marquette,  Michigan 39 

Fig.    26. — A  Monadnock,  Ishpeming,  Michigan 40 

Fig.    27. — Rocks    Folded    and    Crumpled,   Jasper   and    Hematite, 

Ishpeming,  Michigan    .        .        .        .        .        .        .        .41 

Fig.  28. — Map  of  Surface  Rocks,  Illinois,  Wisconsin,  Michigan  .  43 
Fig.    29. — A   Coral  Reef  Exposed   at   Quarry,   Thornton,   Illinois, 

Showing  the  Concentric  Lines  of  Deposit  ...  45 
Fig.    30. — Map  Showing  Land  and  Sea  When  Potsdam  Sandstone 

Was  Depositing  (Upper  Acadian),  after  Schuchert  .  47 
Fig.    31. — Map  Showing  Land  and  Sea  When  Magnesian  Limestone 

Was  Depositing  (Beekmantown),  after  Schuchert  .  .  47 
Fig.    32. — Map  Showing  Land  and  Sea  When  Richmond  Shales  Were 

Depositing  (Cincinnatian),  after  Schuchert  ...  47 
Fig.    2>Z- — Map  Showing  Land  and  Sea  When  a  Part  of  the  Niagara 

Limestone     Was      Depositing     (Mid-Silurian),     after 

Schuchert 47 

Fig.  34. — Animal  Fossils  from  Niagara  Limestone  ....  49 
Fig.    35. — Map  of  the  Late  Paleozoic  When  the  Illinois  Coal  Beds 

W^ere  Depositing  (Upper  Pennsylvanian) ,  after  Schuchert  5 1 
Fig.  36. — Fossils  of  the  Coal  Period  from  Mazon  Creek,  Illinois  .  53 
Fig.    37. — The  Great  Arch  of  Rocks  in  Illinois,  a  Diagram   ;      .        .       54 


Fig.  38 

Fig.  39 

Fig.  40 

Fig.  41 

Fig.  42 

Fig.  43 

Fig.  44 

Fig.  45 

Fig.  46 

Fig.  47 


Chapter  IV 

-Glacial  Map  of  North  America 57 

-Conjectural  Preglacial  River  System 58 

-Angular   and    Striated    Glacial    Bowlder    near    Glencoe, 

Illinois 60 

-Grooves  and  Scratches  on  Bed  Rock  at  Stony  Island  Due 

to  Glacial  Erosion 61 

-Map  of  JNIoraines  in  the  Chicago  Region  .  .  .  .  62 
-Map  of  Moraines  in  Illinois,  from  Bulletin  State  Geological 

Survey 65 

-View  of  Typical  Glacial  Country  a  Few  Miles  Southwest 

of  Chicago 66 

-Flathead,  below  Joliet,  General  View  and  Detail        .        .  67 

-Figures  of  Several  Crystals 68 

-Cleavage  Shown  in  a  Piece  of  Orthoclase  Feldspar     .        .  69 

Chapter  V 


Fig.    48. — The  Wisconsin  Ice  Sheet  at  Its  Maximum  Extension         .       79 
Fig.    49. — An  Old  Shore  Line  of  Lake  Chicago 80 


LIST  OF  ILLUSTRATIONS 


XV 


PAGE 

8i 

83 

84 

85 
86 


Fig.    50. — ^Lakes  Chicago,  Saginaw,  and  Maumee 

Fig.    51. — Lake  Chicago  at  a  Later  Stage  and  Lake  Warren 

Fig.    52. — Lake  Algonquin 

Fig.    53. — Map  Showing  Successive  Shore  Lines  of  Lake  Chicago 
Fig.    54. — Grooves  and  Potholes  in  Bed  of  Outlet  of  Lake  Chicago 

Chapter  VI 

Fig.    55. — Spring  Flowers  of  the  Forest  Floor 91 

Fig.    56. — Fresh- Water  Crustaceans 93 

Fig.    57. — Map  Showing  Relation    of   Rainfall   to  Evaporation  in 

Eastern  United  States 95 

Fig.    58. — Map  pf  Forest,  Prairie,  and  Plains  Regions  in  Eastern 

United  States 96 

Fig.    59. — Diagram  of  Rates  of  Evaporation  in  Contiguous  Regions 

(Adams) 97 

Fig.    60. — The  Cactus  of  the  Dunes,  Opuntia  Rafinesquii    ...  98 

Fig.    61. — The  Six-lined  Lizard,  Cnemidophorus  sexlineatus        .        .  99 

Fig.    62. — Relative  Evaporation  Rates  in  the  Strata  of  the  Forest   .  100 

Fig.    62). — Wild  Lettuce,  Lactuca  scariola loi 

Fig.    64. — Dissected  Leaves  of  Bladderwort,  Hornwort,  and  Milfoil; 

Utricularia,  Ceratophyllum,  Myriophyllum        .        .        .103 

Fig.    65. — Closed  Gentian,  Gentiana  Andrewsli 107 

Fig.    66. — Cup  on  Stem  of  Silphium  perfoliatum  .       .       .        .108 

Fig.    Gy.— Digger  Wcisp,  Bembex  spinolae no 

Chapter  VII 

Fig.    68. — Newly  Formed  Sand  Bar  Offshore  in  Dunes        .        .        -113 
Fig.    69. — Small    Dunes    Held    by    Prostrate    Juniper,    Juniperus 

horizontalis 114 

Fig.    70. — Panne  at  Miller 115 

Fig.    71. — Double  Row  of  Seedlings.     Same  Two  Years  Older  .        .116 

Fig.    72. — Sea  Rocket,  Ca^f/e  ^(/e/^/z^/a 117 

Fig.    73. — Bugseed,  Corispermum  hyssop  if olium 117 

Fig.    74. — Beach  Pea,  Lathyrus  maritimus 117 

Fig.    75. — Cinqueioil,  Potentilla  Anserina 117 

Fig.    76. — Wormwood,  Arlemis la  caudata 117 

Fig.    77. — Rye  Grass,  Elymus  canadensis 117 

Fig.    78. — Winged  Pigweed,  Cycloloma  atriplicijolium  .       .        .        .117 

Fig.    79. — Green  ^l\\k\NQed,  A  cerates  viridiflor a 117 

Fig.    80. — Seaside  Spurge,  Euphorbia  polygonifolia       .        .        .        .117 

Fig.    81. — Cocklehxxr,  Xanthimn  echinaium 118 


XVI 


LIST  OF  ILLUSTRATIONS 


Dune 


Fig.    82. — Sand  Thistle,  Cirsium  Pitcheri 

Fig.    ?>^. — Fore-dune  Association 

Fig.    84. — ^Long-leaved  Sand  Reed,  Calamovilja  longifolia 
Fig.    85. — jMarram,  Ammophila  arenaria 
Fig.    86. — Sand  Cherry,  Primus  pumila  .... 
Fig.    87. — Furry  Willow,  Salix  syrlicola  .... 

Fig.    88. — Cottonwood  Zone 

Fig.    89. — Red-osier  Dogwood  on  Steep  Side  of  Advancing 

Fig.    90. — The  Pine  Association 

Fig.    91. — Bearberry,  Arctostaphylos  Uva-ursi 
Fig.    92. — Arbor  vitae.  Thuja  occidentalis 

Fig.    93. — Shinleaf,  Pyrola  elliptica 

Fig.    94. — Checkerberry,  Gaultheria  procmnbens    . 

Fig.    95. — Prince's  Pine,  Chimaphila  umhellata 

Fig.    96. — Bluebell,  Campanula  rotundijolia   . 

Fig.    97. — Puccoon,  Lithospermum  canescens  . 

Fig.    98. — Horsemint,  Monarda  punctata 

Fig.    99. — St.  John's-wort,  Hypericum  Kalmianum    .  . 

Fig.  100. — Bell  wort.  Uvular  ia  grandiflora 

Fig.  ioi. — Star  Flower,  Trientalis  americana,  and  False  Lily-of-the 

Valley,  Maianthemmn  canadense 
Fig.  102. — Blue-eyed  Grass,  Sisyrinchium  angustijolium 
Fig.  103. — False  Solomon's  Seal,  Smilacma  racemosa    . 
Fig.  104. — Staghorn  Sumac,  Rhus  iyphina 
Fig.  105. — Dwarf  Sumac,  R.  copallina     .... 
Fig.  106. — Aromatic  Sumac,  R.  canadensis 
Fig.  107. — Poison  Sumac,  R.  Vernix        .... 
Fig.  108. — Bittersweet,  Celastrus  scandens    ^  . 
Fig.  109. — The  Frost  Grape,  Vitis  cordijolia  . 
Fig.  1 10. — The  Summer  Grape,  V.  aestivalis  .        .      ' . 
Fig.  III. — The  River-Bank  Grape,  V.  vulpinus 
Fig.  112. — Sassafras,  Sassafras  variifolium 
Fig.  113. — Voison  Ivy,  Rhus  Toxicodendron    . 
Fig.  114. — Shadbush,   Service  Bush,   or  June    Berry,    Amelanchier 

canadensis 

Fig.  115. — Pin  Cherry,  Pruniis  pennsylvanica 

Fig.  116. — Chokecherry,  P.  virginiana     .... 

Fig.  117. — Huckleberry,  Gaylussacia  baccata  . 

Fig.  118. — Bush  Honeysuckle,  Diervilla  Lonicera   . 

Fig.  119. — SpiderwoTt,  Tradescantia  virginica 

Fig.  120. — Bastard  Toadflax,  Comandra  umbellata 


PAGE 

118 
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131 

131 

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133 

133 
^2>2> 


LIST  OF  ILLUSTRATIONS 


xvii 


I'IG. 

121. 

Fig. 

122. 

Fig. 

123. 

Fig. 

124. 

Fig. 

125. 

Fig. 

126. 

Fig. 

127. 

Fig. 

128. 

Fig. 

129.- 

Fig. 

130. 

Fig. 

I3I-- 

Fig. 

132.- 

Fig. 

133.- 

Fig. 

134.- 

Fig. 

I35-- 

FiGo 

136.- 

Fig. 

I37-- 

Fig. 

138.- 

Fig. 

I39-- 

Fig. 

140.- 

Fig. 

141.- 

Fig. 

142.- 

Fig. 

143.- 

Fig. 

144.- 

Fig. 

I45-- 

Fig. 

146.- 

Fig. 

I47-- 

Fig. 

148.- 

Fig. 

149.- 

Fig. 

150.- 

Fig. 

151-- 

Fig. 

152.- 

Fig. 

I53-- 

Fig. 

154.- 

Fig. 

I55-- 

Fig. 

156.- 

Fig. 

I57-- 

Fig. 

158.- 

-Anemone,  Anemone  cylindrica 

-Columbine,  Aquilegia  canadensis 

-Lupine,  Lupinus  perennis 

-Rock  Cress,  Arabis  lyrata 

-Hoary  Pea,  Tephrosia  virginiana 

-Bush  Clover,  Lespedeza  capitata 

-Wild  Geranium,  Geranium  carolinianum 

-Flowering  Spurge,  Euphorbia  corollata 

-Bird's-Foot  Violet,  Viola  pedata 

-Butterfly  Weed,  Asdepias  tuber osa 

-Arrow-leaved  Violet,  Viola  sagittata 

-Louse wort,  Pedicidaris  canadensis  . 

-Wild  Bergamot,  Monarda  fistulosa 

-Blazing  Star,  Liatris  spicata    . 

-Mixed  Oak  Association    . 

-Oaks  of  Chicago  Area 

-Water  Beech,  Carpinus  caroliniana 

-Yellow  Lady's-Slipper,  Cypripedium  parvijlorum 

-Hepatica,  Hepaiica  triloba 

-May  Apple,  Podophyllum  peltatum 

-Wild  Geranium,  Geranium  maculalum 

-Canada  Violet,  Viola  canadensis     . 

-Long-Spur  Violet,  V.  rostrata 

-Rattlesnake  Root,  Prenanthes  alba 

Chapter  VIII 

-Species  of  Tiger  Beetles   .... 
-Termites  or  White  Ants,  Termes  flavipes 
-Sand-colored  Spider,  Trochosa  cinerea   . 
-The  Searcher  and  Fiery  Hunter,  Calosoma  scrutator 

C.  calidum 

-A  Digger  Wasp,  Microbembex  monodonta 

-The  Bee  Fly,  Exoprospa 

-Willow-Leaf  Beetle,  Disonycha  quinqueviltata 

-Snout  Beetle,  Sphenophorus 

-Nest  Holes  of  Bank  Swallows         .... 
-Maritime  Locust,  Trimerotropis  maritima    . 
-Mottled  Sand  Locust,  Sparagemon  wyomingianum 
-Long-horned  Locust,  Psinidia  fenestralis 
-Lesser  Migratory  Locust,  Melanoplus  atlanis 
-Narrow-winged  Locust,  M.  angiistipennis     . 


and 


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XVlll 


LIST  OF  ILLUSTRATIONS 


PAGE 


Fig.  159.- 
Fig.  i6o.- 
Fig.  161.- 
FiG.  162. 
Fig.  163.- 
Fig.  164. 
Fig.  165. 

Fig.  166. 
Fig.  167. 
Fig.  168. 
Fig.  169. 
Fig.  170. 
Fig.  171. 
Fig.  172. 
■  Fig.  173. 
Fig.  174. 


Fig.  175. 
Fig.  176. 
Fig.  177. 
Fig.  178. 
Fig.  179. 
Fig.  180. 
Fig.  181. 
Fig.  182. 
Fig.  183. 
Fig.  184. 
Fig.  185. 
Fig.  186. 
Fig.  187. 
Fig.  188. 
Fig.  189. 
Fig.  190. 
Fig.  191. 
Fig.  192. 
Fig.  193. 
Fig.  194. 
Fig.  195. 
Fig.  196. 


-Sand  Locust,  Ageneotettix  arenosus 

-Longhorn  Beetle,  Monohammus  scutdlatus  . 

-Metallic  Wood-boring  Beetle,  Chalcophora  liherta 

-Chipmunk,  Tamias  striatus  griseus 

-Ant-Lion  and  the  Hole  of  the  Larva 

-A  Click  Beetle,  Lacon  rectangular  is,  Found  beneath  Cactus 

-A    Leaf-eating    Beetle,    Prasocuris    phellandrus,    Found 

beneath  Cactus 

-Blue  Racer,  Coluber  constrictor 
-Puff  Adder,  Heterodon  platirhinos  . 
-Sprinkled  Locust,  Chloealtis  cons  per  sa  . 
-Coral-winged  Locust,  Hippiscus  tuhercidatus 
-Straight-Lance  Grasshopper,  Xiphidium  strictum 
-Sword-bearing  Grasshopper,  Conocephalus  ensiger 

-Six  Typical  Oak  Galls 

-The  Tree  Toad,  Ilyla  versicolor       .... 
-The  Tree  Toad,  H.  picker ingii       .... 

Chapter  IX 

-Interdunal  Swale  of  the  First  Type 

-Caddis  Worm,  Goera 

-Nymph  of  Damsel  Fly,  Lestes  forcipaius 

-Jaws  of  the  Nymph  . 

-Nymph  of  Dragon  Fly,  Celethemis  eponina 

-Adult  of  Dragon  Fly 

-The  Clam,  Lampsilis  luteola    . 

-The  Clam,  Alasmodonta  marginata 

-The  Clam,  Anadonta  grandis  . 

-The  Pike,  Esox  lucius 

-The  Shiner,  Notropis  atherinoides 

-Chara 

-The  Bluegill,  Lepomis  pallidus 

-Pumpkin  Seed,  Eupomolis  gibhosus 

-Nymph  of  the  Dragon  Fly,  Gomphus  spicatus 

-Mud  Minnow,  Umbra  litni      .... 

-Golden  Shiner,  Abramis  crysoleucas 

-Chub  Sucker,  Erimyzon  sucetta 

-Brown  or  Spotted  Bullhead,  Ameiurus  nebulosus 

-Tadpole  Cat,  Schilbeodes  gyrinus    . 

-Nymph  of  Damsel  Fly,  Ischnura  verticalis 

-Buttonbush,  Cephalanthus  occidental  is  . 


LIST  OF  ILLUSTRATIONS 


XIX 


PAGE 

Fig.  197. — Pennsylvania  Saxifrage,  Saxifraga  pennsyhanica        .       .     178 

Fig.  198. — Sensitive  Fern,  Onoclea  sensibilis 179 

Fig.  199. — Sour  Gum,  Nyssa  sylvatica 180 

Fig.  200. — Swamp  Holly,  Ilex  verticillata 181 

Fig.  201. — Meadowsweet,  Spiraea  latijolia      .        .        .        .       .       .181 

Fig.  202. — Steeplebush,  S.  tomentosa 181 

Fig.  203. — Royal  Fern,  Osmunda  regalis  .        .        .        .        .        .        .182 

Fig.  204. — Clayton's  Fern,  Osmunda  Claytoniana  .        .        .        .        .     182 

Fig.  205. — Cmndim.onYQxn,  Osmimda  cinnamomea         .        .        .        .     182 

Fig.  206. — Second  Type  of  Pond 183 

Fig.  207. — Shruhhy  Cmq\itio\\,  Poteniilla  fruticosa        .        .        .        .      184 

Fig.  208. — ^A  Small  Clam,  Sphaerium  simile 184 

Fig.  209. — Nymph  of  Anax 184 

Fig.  210. — Nymph  of  Leucorhinia  iniacla,  after  Shelford  .  .  .  185 
Fig.  211. — Adult  Libellula  pulchella,  ivouiNeedhnTa  ....  185 
Fig.  212,  a  and  B — Aquatic  Insects  and  Their  Young  .        .      186,  187 

Fig.  213. — Diving  Spider,  Dolomedes  sexpunctatus         .        .       .        .188 

Fig.  214. — The  Eft,  Diemictylus  viridescens 189 

Fig.  215. — Garden  Spider,  Argiope 190 

Fig.  216. — Tettix  graniilatiis ,  Tettigidea  lateralis 190 

Fig.  217. — Short-horned  Locust,  Tryxalis  brevicornis  ....  191 
Fig.  218. — Short-winged  Green  Locust,  Dichromorpha  vlridus  .  .191 
Fig.  219. — Slender-bodied  Locust,  Leptysma  marginicolUs    .        .        .      191 

Fig.  220. — Hoosier  Locust,  Paroxya  hoosieri 191 

Fig.  221. — Scudder's  Paroxya,  P.  scudderi 191 

Fig.  222. — Striped  Ground  Cricket,  Nemobi  us  fascial  us  .  .  .  192 
Fig.  223. — Leather-colored  Locust,  Schistocerca  alutacea  .  .  .  192 
Fig.  224. — Nebraska  Locust,  Phaetalioles  nebrascensis  .  .  .  .192 
Fig.  225. — Marsh  Conehead,  Conocephalus  palustris      ....     192 

Fig.  226. — A  Sphagnum  Bog 193 

Fig.  227. — The  Slender  Sedge,  Carex  Jiliformis 193 

Fig.  228. — The  Shore  Sedge,  C  riparia 193 

Fig.  229. — ^An  Orchis,  Arelhusa  bulbosa .      194 

Fig.  230. — The  Bearded  Orchis,  Calapogon  pulcheUus    .       .        ,        .194 

Fig.  231. — ^The  Sundew,  Drosera  rotundijolia 195 

Fig.  232. — 'Tickseed,  Coreopsis  grandiflora 195 

Fig.  233, — Cottony  Grass,  Eriophorum  gracile        .        .        .        ...      195 

Fig.  234. — Swamp  Horsetail,  Equisetum  fluvlatile 195 

Fig.  235. — Swamp  Fern,  Aspidium  Thelypteris 195 

Fig.  236. — Sphagnum  Moss .        .       .        .     195 

Fig.  237. — Ragged  Orchis,  Habenaria  lacera 196 


XX 


LIST  OF  ILLUSTRATIONS 


Fig.  238. — Fragrant  Ladies'  Tresses,  Spiranihes  Romanzoffiana 

Fig.  239. — Leatherleaf,  Chamaedaphne  calyculata 

Fig.  240. — Pitcher  Plant,  Sarracenia  purpurea 

Fig.  241. — Andromedsi,  Andromeda  Polifolia  . 

Fig.  242. — Chokeberry,  Pyrus  arhiitljolia 

Fig.  243. — 'R.ViSh.  Asttr,  Aster  junceus 

Fig.  244. — Crested  Shield  Fern,  Aspidium  cristatum 

Chapter  X 

Fig.  245. — Tulip  Tree,  Leaf  and  Flower,  Lirodendron  Tulipifera 
Fig.  246. — White  Walnut,  Juglans  cinerea       .... 

Fig.  247. — Black  Walnut,  /.  nigra 

Fig.  248. — Black  Cherry  Trunk,  Rruniis  seroiina  .... 
Fig.  249. — Hackberry  Trunk,  Celtis  occidenlalis,  and  Trunk  of  Beech 

Fagiis  grandifolia 

Fig.  250. — American  Elm,  Ulmus  americana 

Fig.  251. — Sycamore  Leaf  and  Fruit,  Plataniis  occidentalis  . 

Fig.  252. — Climax  Forest  Showing  Stratification    .... 

Fig.  253. — Hard  Maple  Leaf  and  Fruit,  Acer  saccharmn 

Fig.  254. — Flowering  Dogwood,  Leaf  and  Blossom,  Cornus  florida 

Fig.  255. — Twig  of  Witchhazel,  Hamamells  virginiana  . 

Fig.  256. — Pawpaw,  Leaves,  Blossom,  and  Fruit,  Asimina  triloba 

Fig.  257. — ^Leaf  and  Fruit  of  Hop  Hornbeam,  Ostrya  virginiana 

Fig.  258. — Redbud  Leaf  and  Blossom  Cluster,  Cercis  canadensis 

Fig.  259. — High  Bush  Cranberry,  Viburnum  opulus 

Fig.  260. — Nannyberry,  V.  lentago    .... 

Fig.  261. — Wahoo,  Evonymus  atropurpureus    . 

Fig.  262. — Elderberry,  Sambucus  canadensis    . 

Fig.  263. — Strawberry  Bush,  Evonymus  americana 

Fig.  264. — Jack-in-the-Pulpit,  Arisaema  triphyllum 

Fig.  265. — Pigeon  Berry,  Cornus  canadensis    . 

Fig.  266. — Green  Dragon,  Arisaema  dracontium 

Fig.  267. — Baneberry,  Actaea  alba    . 

Fig.  268. — Waterleaf,  Hydrophyllmn  virginianum 

Fig.  269. — Sweet  Cicely,  Osmorhiza  Claytoni 

Fig.  270. — Clearweed,  Pilea  pumila  . 

Fig.  271. — Bedstraw,  Galium  aparine 

Fig.  272. — Ginseng,  Panax  trijolium 

Fig.  273. — Touch-me-not,  Impatiens  pallida 

Fig.  274. — Beech  Fern,  Phegopteris  polypcdioides 

Pig.  275. — Maiden-Hair  Fern,  Adiantum  pedatum 

Fig.  276. — W^ood  Spleen  wort,  Asplenium  acrostichoides 


LIST  OF  ILLUSTRATIONS 


XXI 


Fig.  277. — Pale  Wood  Fern,  Aspidium  novahoracense 
Fig.  278. — Christmas  Fern,  Polystichium  acrostichoides 
Fig.  279. — ^Lady  Fern,  Asplenium  Filix-femina 
Fig.  280. — Margined  Fern,  Aspidium  marginale 
Fig.  281. — Florists'  Fern,  A.  spinulosum 
Fig.  282. — Ostrich  Fern,  Onoclea  struthiopteris 
Fig.  283. — Bracken  Fern,  Pteris  aquilina 
Fig.  284. — Species  of  Polygyra   .... 

Fig.  285. — Land  Mollusca 

Fig.  286. — Common  Mole,  Scalopus  aquaticus 

Fig.  287. — White-footed  Deer  Mouse,  Peromyciis  leucopus  . 

Fig.  288. — The  Common  Slug,  Agriolimax  campestris   . 

Fig.  289. — The  Large  Millipede,  Spiroholus  marginatus 

Fig.  290. — The  Yellow-margined  Centipede,  Fontaria  corrugate 

Fig.  291. — The  Red  Centipede,  Geo/>/«7w5  rw5e;w   . 

Fig.  292. — The  Eyed  Elater,  Alaus  oculatus    .... 

Fig.  293. — Blatchley's  Locust,  Melanoplus  hlatchleyi     : 

Fig.  294. — The  Horned  Passalus  and  Its  Larva,  Passalus  cornutus 

Fig.  295. — Several  Beetles  Common  in  Fungi,  Diaperis  maculata 

Pisenus  humeralis,  Boletotherus  bifurcus 
Fig.  296. — The  Wood  Frog,  Rana  sylvatica 
Fig.  297. — The  Pawpaw  Swallowtail,  Papilio  ajax 
Fig.  298. — The  Spicebush  Swallowtail,  P.  troilus   . 
Fig.  299. — Cicada  and  Larva,  Cicada  linnei    . 
Fig.  300. — Tree  Crickets  of  Several  Species    . 
Fig.  301. — Twig  Pruner  of  Oak,  Elaphidion  villosum 
Fig.  302. — A  Leaf  Beetle,  Chalepus  rubra 
Fig.  303. — A  Nut  Borer,  genus  Balaninus 

Fig.  304. — Spider,  Epeira  gigas 

Fig.  305. — Spider,  Neocosoma  arabesca 

Fig.  306. — The  Jumping  Spider,  Phidippus  audax 

Fig.  307. — Camel  Cricket,  Ceuthophilus  maculatus 

Fig.  308. — Rustic  Borer,  Xylotrechus  colonus 

Fig.  309. — Elm  Borer,  Saperda  tridentata 

Fig.  310. — Graphisurus  fasciatus,  a  Beetle 

Fig.  311. — Calloides  nobilis,  a  Beetle 

Fig.  312. — Motor ckus  bimaculatus,  a  Beetle 

Fig.  313. — Flathead  Apple-Tree  Borer,  Chrysobothris  Jemorata 

Fig.  314. — Heartwood  Borer,  Parandra  brunea 

Fig.  315. — Oak  Borer,  Eupsalis  minuta    . 

Fig.  316. — Beetle,  Nyctobates  pennsylvanica     . 

Fig.  317. — Beetle,  Tenebrio  tenebrioides    . 


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XXll 


LIST  OF  ILLUSTRATIONS 


Fig.  318. — Jumping  Mouse,  Zapus  hudsoniiis 

Fig,  319. — Gray  Gopher,  CiteUus  franklini      .... 

Fig.  320. — Woodchuck,  Marmot  a  monax         .... 

Fig.  321. — The  Painted  Lady,  Pyrameis  cardiii 

Fig.  322. — Round-winged  Katydid,  Amhlycorypha  rotundijolia 

Fig.  323. — Oblong-winged  Katydid,  A.  oblongifolia 

Chapter  XI 

Fig.  324. — Water  Snails 

Fig.  325. — Blob  or  Miller's  Thumb,  Cottus  ictalops 

Fig.  326. — One  of  the  Pond  Weeds,  Potamogeton  natans 

Fig.  327. — Scirpus  atrovirens 

Fig.  328. — S.  Torreyi   . 

Fig.  329. — 5*.  valid  us    . 

Fig.  330. — J  uncus  balticus  . 

Fig.  331. — /.  tenuis 

Fig.  332. — J.  canadensis 

Fig.  S33- — J-  cfusus    . 

Fig.  334. — Eleocharis  acicularis 

Fig.  335. — The  Bulrush  Zone     .... 

Fig.  336. — Bur  Reed,  Sparganium  eurycarpum 

Fig.  337. — Arrowhead,  Sagitiaria  latijolia 

Fig.  338. — Wild  Rice,  Zizania  aquatica    . 

Fig.  339. — The  Reed,  Phragmites  communis    . 

Fig.  340. — Sweet  Flag,  Acorus  Calamus   . 

Fig.  341. — Painted  Turtle,  Chrysemys  marginata 

Fig.  342. — Snapping  Turtle,  Chelydra  serpentina 

Fig.  343. — Bullfrog,  Rana  catesheiana 

Fig.  344. — Pickerel  Frog,  Rana  palustris 

Fig.  345. — Nest  of  Marsh  Wren 

Fig.  346. — American  Bittern,  Botaurus  lentiginosus 

Fig.  347. — Forked-Tail  Katydid,  S c udder ia  fur cata 

Fig.  348. — Texas  Katydid,  S.  texensis 

Fig.  349. — Carex  conjuncta 

Fig.  350. — C.  cristata   .... 

Fig.  351. — C.  lupuliformis  . 

Fig.  352. — C.  stricta     .... 

Fig.  353. — Slough  Grass,  Spartina  Michauxiana    . 

Fig.  354. — Blue-Joint  Grass,  Calamagrostis  canadensis 

Fig.  355. — Fowl  Meadow  Grass,  Glyceria  nervata  . 

Fig.  356. — Switch  Grass,  Panicum  virgatum    . 

Fig.  357. — Thin  Grass,  Agrostis  perennans 


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LIST  OF  ILLUSTRATIONS 


XXlll 


Fig. 
Fig. 
Fig. 

Fig. 
Fig. 

Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 


Fig.  383 


Fig. 

384-- 

Fig. 

385. 

Fig. 

386. 

Fig. 

387- 

Fig. 

388. 

Fig. 

389.- 

Fig. 

390. 

358. — Andropogon  furcatus 

359. — Luxuriant  Grasses  of  Wet  Prairie 

360. — Sin?iitwee6,  Polygonum  lapathifolmm    . 

361. — Chickweed,  Cerastium  vulgaiiim 

362. — ^Three  Species  of  Cardamine:  C.  Doiiglassii,   C.  hulhosa 

C.  pennsylvanica 

363. — Mermaid  Weed,  Proserpinaca  palustris 
364. — Skull  Cap,  Scutellaria  galericulata 
365. — Cardinal  Flower,  Lobelia  cardinalis 
366. — Shooting  Star,  Dodecatheon  meadia 
367. — Wild  Hyacinth,  Camassia  esculenta 
368. — Wild  Onion,  Allium  cernuum  .... 
369. — Culver's  Root,  Veronica  virginica  . 
370. — Golden  Old  Man,  Zizia  aurea 
371. — Brown-eyed  Susans,  Rudbeckia  hirta 
372. — Coneflower,  Brauneria  purpurea 
373. — Rosinweed,  Silphium  terebinthinaceum  . 
374. — Dropseed  Grass,  Sporobolus  cryptandrus 
375. — Prairie  Phlox,  Phlox  pilosa      .... 
376. — Rattlesnake  Master,  Eryngium  yucciJoUum 
377. — Prairie  Clover,  Petalostemum  purpureum 
378. — Lead  Plant,  Amorpha  canes cens 
379. — Chimney  of  Burrowing  Crayfish     . 
380. — Striped  Gopher,  Citellus  tridecemlineatus 
381. — Pocket  Gopher,  Geomys  bursarius  . 
382. — Pennsylvania  Meadow  Mouse,  Microtiis  pemisylvanicus 
a,  The  Two-lined  Locust,  Melanoplus  bivittatus;  b,  Red- 
legged  Locust,  M.femur-rubrum;  c,  The  Short-winged 

j  Grasshopper,  Xiphidium  brevipenne;  d,  The  Meadow 
Grasshopper,  Orchelmium  vulgare;  c,  The  Sprinkled 
Grasshopper,  Chlocaltis  conspcrsa;  J.  The  Green- 
legged  Locust,  Melanoplus  vlridipes 

— Sawflies  and  Larvae 

The  Cutworm  and  Its  Moth,  Feltia  subgothica    . 

— The  Salt-Marsh  Caterpillar,  Estigmena  acraea     . 

— The  Yellow  Bear  Caterpillar,  and  Moth,  Diacrisia  virginica 

— The  Woolly  Bear  Caterpillar,  and  Moth,  Isia  isabella 

Chapter  XII 

— Bluff  with  Xerophytic  Vegetation 

— The  Common  Scouring  Rush,  Equisetum  hyemale 


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XXIV 


LIST  OF  ILLUSTRATIONS 


Fig.  391. — Clay-Bank  Spider,  Pardosa  lapidicina 

Fig.  392. — Mouth  of  Ravine 

Fig.  393. — Ravine  with  Vegetation  on  Sides   . 

Fig.  394. — Sarsaparilla,  Aralia  nudicaulis 

Fig.  395. — Fragile  Fern,  Cystopteris  fragilis     . 

Fig.  396. — Bladder  Fern,  C.  bulbifera       .... 

Fig.  397- — A  Common  Liverwort,  Marchantia  polymorpha 

Fig,  398. — Selaginella 

Fig.  399. — Meadow  Rue,  Thalictrum  dasycarpmn 

Fig.  400, — Boneset,  Eupatorium  perfoliatum   . 

Fig.  401. — Queen  Anne's  Lace,  Wild  Carrot,  Daiicus  Carota 

Fig.  402. — Leaf  and  Fruit  of  Wild  Parsnip,  Pastinaca  sativa 

Fig.  403. — Leaf  of  Angelica,  Angelica  atropiirpurea 

Fig.  404, — Alumroot,  Heuchera  americana 

Fig.  405. — Whitlow  grass,  Draba  caroliniana 

Fig.  406. — Rattlebox,  Crotalaria  sagittalis 

Fig.  407. — Walking  Fern,  Camptosorus  rhizophyllus 

Fig.  408. — Wild  Hydrangea,  Hydrangea  arhorescens 

Fig.  409. — Rock  Polypody,  Polypodimn  vulgare 

Fig.  410. — Toad  Bug,  Gclastocoris  oculatus 

Fig.  411. — Hooded  Grouse  Locust,  Paratettix  cucidlatus 

Fig.  412. — Spotted  Sandpiper 

Fig.  413. — Long-bodied  Spider,  Tetragnatha  lahoriosa 
Fig.  414, — Kentucky  Coffee  Tree,  Gymnodadus  dioica 
FiG.  415. — Vines  Draped  on  Trees  in  River  Bottom 
Fig.  416. — Bladdernut,  Staphylea  trifoUa 
Fig.  417. — Prickly  Ash,  Zanthoxylum  americanum 
Fig.  418. — Moonseed,  Menispermum  canadense 
Fig.  419, — Smilax,  Smilax  hispida     .        ,        .        . 
Fig.  420. — Skunk  Cabbage,  Symplocarpiis  foetidus 
Fig.  421, — Cheveril,  Chaerophyllum  procumbens 
Fig.  422. — Fringed  Loosestrife,  Steironema  ciliatum 
Fig.  423. — Honewort,  Cryptotaenia  canadensis 
Fig.  424. — Cow  Parsnip,  Ilieracleum  lanaimn 
Fig.  425. — Short-tailed  Shrew,  Blarina  brevicaudata 

Chapter  XIII 

Fig,  426. — 'Nymphs  of  Anax,  Aeschna,  and  Boyeria,  dragon  flies 
Fig,  427. — Horned  Dace,  Semotilns  atromaculatus  ,        .        .        . 
Fig.  428. — Red-bellied  Dace,  Chrosomus  erythrogaster    . 
Fig.  429. — Blunt-nosed  Minnow,  Pimephales  notatus 


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LIST  OF  ILLUSTRATIONS 


XXV 


Fig.  430. 
Fig.  431. 
Fig.  432. 
Fig.  433- 
Fig.  434. 
Fig.  435. 
Fig.  436. 
Fig.  437. 
Fig.  438. 
Fig.  439. 
Fig.  440. 
Fig.  441. 
Fig.  442. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 
Fig. 


443. 
444. 

445- 
446. 

447- 


448. 


Fig.  449.- 
FiG.  450.- 
FiG.  451.- 
FiG.  452.- 


-  Johnny  Darter,  Boleosoma  nigrum 
-Rainbow  Darter,  Etheo stoma  coeruleum 
-Common  Sucker,  Catostomus  commersonii    . 
-Stone  Roller,  Campostoma  anomaliim     . 
-Top  INIinnow,  Fundulus  dispar 
-Hog  Sucker,  Catostomus  nigricans 
-Straw-colored  Minnow,  Notropis  hlennius     . 
-Rock  Bass,  AmblopUtes  rupestris    . 
-Black  Crappie,  Pomoxis  sparoides 
-Sucker-mouthed  Minnow,  Phenacohius  mirabilis 
-Fan -tailed  Darter,  Ethcostoma  flahellarc 
-Black-sided  Darter,  Hadropterns  aspro 
-Sharp-headed  Darter,  Hadropterns  phoxocephalus 
-Net  Building  Caddis  Fly,  Hydropsyche 
-Caddis-Fly  Larva,  Helicopsyche 
-Water  Penny,  Larva  of  Psephemis  lecontei   . 
-Brook  Beetle,  Psephenus  lecontei    ... 

-A  Common  Rotifer 

-The  Lower  Galien  River — Plant  Zonation  in  Foreground 

Chapter  XIV 

-Map  of  Potato-Beetle  Invasion 

-Map  of  Cotton-Boll  Weevil 

-Map  of  Tree  Distribution 

-Map  of  Chicago  Localities 


PAGE 
282 

283 
283 
283 
284 
284 

285 
286 
286 
286 
287 
288 
288 
288 
288 
288 
290 


299 
301 
302 

311 


^ 


CHAPTER  I 


THE  CHANGING  FACE  OF  NATURE 

HICAGO  is  the  center  of  a  region  of  quiet 
but  varied  beauty.  He  who  limits  his 
excursions  to  the  city  parks  or  the  im- 
mediate vicinity  of  the  city  sees  only  a 
monotonously  level  plain,  but  to  him 
who  wanders  along  the  North  Shore, 
explores  the  Dunes,  or  rambles  over  the 
wooded  hills  of  the  nearby  moraine 
country  there  are  presented  bits  of  landscape  that  charm  even  the 
casual  observer  with  their  wealth  of  form  and  color.  The  encir- 
chng  horizon  line  shrouded  in  the  shimmering  haze  of  the  lake  or 
broken  by  the  billowy  hills,  the  nearby  woodlands,  the  cloud 
shadows  that  play  among  them,  the  cleared  land  checkered  by 
its  varied  harvests  or  dotted  with  grazing  cattle,  the  brook 
playing  hide  and  seek  among  the  tangled  shrubs  and  ferns,  the 
bird  song  whistled  from  the  bough  tip— all  are  sources  of  exqui- 
site pleasure.  Poet  and  painter  fairly  astound  us  with  the  revela- 
tion of  beauty  which  they,  with  fine  sensitiveness,  perceive  in 
even  so  commonplace  an  outlook.  Science  too  is  a  revealer.  It 
adds  a  third  dimension  to  the  landscape;  it  gives  depth.  It 
delves  below  the  surface  to  the  foundation.  It  gives  the  per- 
spective of  time.  To  the  thoughtful  man  the  outstretched  view 
is  not  alone  a  beautiful  prospect;  it  is  a  voice  from  the  past  and 
speaks  of  history  as  eventful  as  do  the  care-wrought  furrows  of 
the  human  face. 

Many  agencies  of  land  formation,  disintegration,  and  alter- 
ation have  been  at  work  in  times  past  to  produce  the  present 
features  of  this  region,  and  most  of  them  are  still  at  work  chan- 
ging its  appearance  slowly  but  surely.     Go  out  along  the  shore 


nonamr  iAkamt 

N.  C  State  CoUegt 


2  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

where  high  clay  bluffs  stand  at  the  water's  edge,  as  at  Fort 
Sheridan  or  Lakeside,  and  see,  during  a  storm,  the  pounding 
waves  gnawing  at  their  bases.  As  they  are  undermined  the 
unsupported  upper  portions  slide  down,  carrying  the  vegetation, 
even  the  trees,  the  soil,  and  contained  bowlders  into  the  insatiable 
maw  of  the  lake  (Fig.  i),  all  to  be  ground  up  by  the  wave  action 
and  deposited  in  time  out  in  quiet  water  as  beds  of  sand  or  clay. 


Fig.  I. — Clay  bluffs  near  Winnetka  on  shore  of  Lake  Michigan,  showing 
erosion.  The  base  is  torn  up  by  waves  and  the  whole  unsupported  side  is  moving 
down,  as  shown  by  shrubs  and  trees  in  various  stages  of  transit  from  top  to  bottom. 

or  transported  and  thrown  up  on  shore  in  sandy  or  muddy 
beaches.  This  process  of  wave  erosion  and  deposition  goes  on 
ceaselessly  and  has  been  going  on  for  ages,  not  only  on  the  shores 
of  Lake  Michigan,  but  wherever  land  masses  are  exposed  to  the 
attacks  of  the  waves.  Serried  ranks  of  billows  (Fig.  2)  armed 
with  rock  fragments  hurl  themselves  in  relentless  fury  on  the 
slow-retreating  land.  -The  softer  portions  of  the  shores,  even 
the  rock-bound  shores,  in  the  age-long  battle  are  worn  away 
rapidly  and  form  deep  bays.     The  more  resistant  sections  stand 


THE  CHANGING  FACE  OF  NATURE 


out  as  bold  headlands,  only  in  time  to  also  yield  to  the  continu- 
ous charges  (Frontispiece).  When  it  is  realized  that  this  battle- 
line  of  sea  and  land  is  175,000  miles  long  and  that  in  a  storm 
the  waves  strike  with  the  force  of  several  tons  per  square  foot 
and  bombard  the  shore  with  rock  fragments  that  weigh  up  to  a  ton, 
it  is  evident  that  the  oceans  and  the  great  lakes  have  been  and 
still  are  mighty  agents  of 
erosion,  in  time  destroying 
even  the  most  resistant  land 
masses. 

Running  water  in  rivu- 
lets, creeks,  and  rivers  is 
another  powerful  agent  of 
land  erosion.  Follow  any 
stream  and  you  will  not  have 
traveled  far  before  you  will 
find  some  place  where  it  is 
cutting  its  banks  (Fig.  3). 
Thorn  Creek,  near  Glenwood, 
Salt  Creek,  one-half  mile  up- 
stream from  Brookfield,  the 
Desplaines  at  Lockport,  and 
Fraction  Run,  above  Delwood 
Park,  give  excellent  demon- 
strations of  the  cutting  power  of  a  stream.  In  newly  upheaved 
sections,  like  mountain  areas,  the  streams  are  torrents  (Fig.  4) 
that  wear  down  their  narrow  valleys,  cutting  deeply  and 
rapidly,  both  by  virtue  of  their  terrific  force  and  by  the 
angular  rock  fragments  they  carry  that  act  as  graving  tools. 
When  the  stream  has  cut  down  to  somewhere  near  the  level  of  the 
body  of  water  into  which  it  flows,  it  runs  more  slowly,  meanders 
back  and  forth  across  its  valley,  attacking  and  undermining  the 
bounding  hills,  thus  gradually  widening  its  influence.  Then  its 
valley  changes  from  the  deep  and  narrow  canyon  of  a  young 
stream  to  the  broader  basin  of  an  old  river  (Fig.  448).     A  river 


Fig.  2. — Ranks  of  billows 


4  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

valley,  then,  is  largely  the  work  of  the  stream  it  contains.  The 
whole  valley,  limiting  hills,  meanders,  flood  plain,  cuttings,  and 
fills,  may  be  seen  in  perfection  in  many  of  the  smaller  streams, 
such  as  Salt  Creek  near  Brookfield,  Thorn  Creek  near  Thornton, 
Pettibone  Creek  at  North  Chicago. 


Fic.  3. — A  stream  cutting  its  banks.     Photo  by  Fuller 

The  Chicago  region  shows  many  stages  in  the  formation  of 
the  valley.  Where  the  lake  shore  is  high,  as  it  is  from  Glencoe 
northward  or  on  the  eastern  shore  from  New  Buffalo  north, 
the  melting  snows  and  spring  rains  find  their  way  to  the  shore 
along  irregular  depressions,  then  plunge  down  the  steep  bank  in 
headlong  turmoil,  cutting  rapidly  a  steep-sided  ravine.  Gradu- 
ally the  stream  eats  its  way  back  toward  the  relatively  level 
meadowland.     You  may  follow  down  its  course  from  where  the 


THE  CHANGING  FACE  OF  NATURE 


Fig.  4. — A  mountain  torrent.     Note  the  valley  is  steep-sided 


Fig.  5. — The  beginnings  of  a  ravine 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


little  runnel  is  starting  out  from  some  grassy  depression  (Fig.  5), 
pass  the  fairly  level  upper  stretches  where  it  meanders,  cutting 
an  irregular  course  as  it  grows  by  minor  tributaries,  enter  the 
V-shaped  valley  (Fig.  6)  in  which  it  is  flowing  with  irresistible 
vigor  straight  for  its  goal — a  valley  that  deepens  and  widens  with 
every  advance — and  finally  arrive  where  for  a  few  rods  it  may 
proceed  a  placid  little  river  just  before  it  enters  the  lake. 


Y 


Fig.  6. — A  later  stage,  the  deep  V-shaped  ravine 

Valleys  which  exemplify  similar  stages  of  development  are 
seen  where  the  stream  cuts  its  way  down  through  the  rock,  only 
in  this  case  the  valley  sides  are  likely  to  be  very  precipitous  if 
the  cutting  is  at  all  recent,  since  it  takes  much  longer  for  the 
forces  of  erosion  to  crumble  down  the  valley  sides.  No  better 
illustration  of  such  valleys  cut  out  of  the  rock  can  be  found  than 
those  exhibited  in  the  neighborhood  of  Starved  Rock  on  the 
Illinois  River,  Oregon  on  the  Rock  River,  and  the  Dalles  of 
the  Wisconsin  (Fig.  7),  all  beauty  spots  easily  accessible  from 
Chicago.  Standing  on  the  top  of  Starved  Rock,  the  valley 
lies  spread  out  before  your  eye,   bounded  on  either  side  by 


THE  CHANGING  FACE  OF  NATURE 


Fig.  7.— The  Dalles  of  the  Wisconsin.    The  trees  on  the  rocks  at  right  are 
white  pines,  Pinus  strobus.    The  rock  is  St.  Peter's  sandstone. 


8  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

precipitous  hills  (Fig.  8).  The  rock  of  the  region  is  a  rather  soft 
sandstone  and  the  river  has  cut  its  way  deeply  into  this,  scouring 
out  its  valley  as  it  shifts  from  side  to  side  in  its  meandering  way. 
The  surrounding  country  is  slightly  rolling  farm  land,  giving 
the  impression  of  a  level  plain.  It  is  startling  to  walk  or  drive 
across  this  country  and  then  suddenly  find  yourself  on  the  brink 
of  a  deep  valley  with  precipitous  sides,  loo  feet  sheer,  and  look 


Fig.  8. — The  Valley  of  the  IHinois  River,  looking  from  Starved  Rock  to  the 
bluffs  on  the  opposite  side. 

across  to  the  opposite  side,  3  or  4  miles  away.  The  tributary 
streams  flowing  to  the  river  from  the  plain  plunge  down  in  foam- 
ing falls  wliich  eat  their  way  back  through  the  sandstone,  form- 
ing narrow  chasms  that  end  abruptly  at  their  head  in  a  rock  wall 
down  which,  when  the  stream  is  full,  the  water  thunders  (Fig.  9). 
There  is  a  small  but  very  interesting  rock  canyon  cut  in  the 
limestone  on  the  south  side  of  the  valley  of  the  '^  Calumet 
Feeder"  i  mile  east  of  ''Sag"  Station  on  the  Chicago  &  Joliet 
Interurban  (Fig.  393).     Fraction  Run  cuts  through  the  limestone 


THE  CHANGING  FACE  OF  NATURE 


Fig.  g. — A  narrow  rock  ravine  ending  in  a  waterfall.     Deer  Park  Canyon  near 
Star\'ed  Rock.     Photo  by  O.  W.  Caldwell. 


Fig.  io.— In  the  Canadian  Rockies,  a  glacier  made  by  the  confluence  of 
several  smaller  glaciers  emanating  from  the  snow  fields  on  the  mountains  in  the 
background. 


lO 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


and  makes  some  short  canyons  near  Joliet,  one  of  which  is  included 
in  Delwood  Park.  Sugar  Creek  has  cut  a  gorge  nearly  fifteen 
feet  deep  in  the  suburbs  of  Joliet,  crossed  by  the  Chicago  & 
Alton  main-line  tracks  going  south. 

Water  may  be  quite  as  efficient  an  agent  of  land  destruction 
when  running  underground  as  it  is  when  on  the  surface,  particu- 
larly in  limestone  regions.     Percolating  through  soil  filled  more 


Fig.  II. — Clay  pinnacles,  erosion  remnants,  near  Lakeside,  Mich.  Note 
white  pine,  Finns  strobus,  and  juniper,  Juniperus  communis,  on  crest.  Inset, 
details  of  other  nearby  pinnacles. 

or  less  with  disintegrating  organic  matter  that  liberates  CO^  the 
water  becomes  charged  with  this  gas.  In  such  a  condition  its 
power  to  dissolve  limestone  is  relatively  great.  Following  some 
crevice,  joint,  or  bedding-plane,  the  water  excavates  the  rock, 
carries  it  away  in  solution,  and  underground  caverns  are  formed, 
at  times  of  great  extent  and  wonderful  beauty.  While  none  are  to 
be  found  in  the  immediate  Chicago  region  except*  small  ones 
discovered  as  the  limestone  is  quarried,  yet  we  are  near  enough 


THE  CHANGING  FACE  OF  NATURE  ii 

to  the  caverns  of  southern  Indiana  and  of  Kentucky  so  that  their 
fame  is  familiar. 

In  frigid  regions  the  rivers,  which  in  our  latitude  rise  in  lakes 
and  pursue  their  lively  way  down  the  outletting  valleys,  may  be 
replaced  by  streams  of  ice  (Fig.  lo)  which  take  their  origin  in 
the  great  snow  fields  of  the  mountain  basins  and  plow  their 
way  down  the  valleys  slowly  but  with  irresistible  force.  The 
loose  soil  is  pushed  before  them;  the  solid  rock  is  worn  away  by 
the  terrific  grinding  force  of  the  ice,  hundreds  of  feet  deep,  hold- 
ing in  its  grip  the  fragments  of  rock  that  abrade  like  giant's 
sandpaper  in  the  hands  of  Hercules.  Once  upon  a  time,  as  will 
be  detailed  later,  the  Chicago  region  was  covered  by  the  glacial 
ice  cap  that  overspread  nearly  all  of  northern  North  America. 
The  surface  of  the  bed  rock  here  is  planed  off,  covered  with 
scratches  and  parallel  grooves  made  by  the  moAung  ice  sheet 
(see  Fig.  41),  and  the  earth  that  overlays  the  rock  is  full  of 
bowlders  of  granite,  greenstone,  diorite,  and  other  foreign  rock 
transported  from  the  ledges  far  to  our  north,  worn  smooth  and 
scored  with  striations  in  their  progress  (see  Fig.  40). 

The  pelting  rain  is  no  insignificant  agent  of  erosion.  Each 
drop  seems  a  puny  thing,  but  multiply  them  endlessly  and  let 
them  act  age  after  age  and  they  do  wear  awa}^  the  land.  The 
wash  on  steep  hillsides  is  very  apparent.  The  water  runnels 
during  the  heavy  rains  cut  steep-sided  valleys,  between  which 
there  stand  up  sharp-edged  clay  ridges  and  pinnacles  (Fig.  11). 
These  serve  to  call  attention  strikingly  to  an  agency  that  works 
so  unobstrusively  it  might  easily  go  without  notice.  Such 
pinnacles  in  clay,  the  result  of  rains  and  spring  freshets,  are  seen 
along  the  lake  shore  as,  for  instance,  near  Lakeside  where  the 
clay  moraine  comes  to  the  lake.  In  a  similar  way  the  rock  itself 
is  worn  away  by  the  pelting  rain,  and  pinnacles  are  left  standing 
mute  testimony  of  the  former  height  of  all  the  land,  now  largely 
gone  through  erosion. 

The  heave  of  water  in  the  rock  crevices  when  it  transforms 
to  ice  is  another  destructive  action  of  water.     Man  realizes  its 


12 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


might  when  it  fragments  the  cement  sidewalk  or  tears  the 
plaster  from  the  exterior  of  a  house.  But  it  is  quite  as  powerful 
when  it  operates  on  the  rock  of  a  cliff  or  the  disintegrating 
bowlder.  At  the  base  of  a  rock  cliff  is  often  found  a  pile  of  rock 
debris,  the  talus,  the  accumulation  of  the  incessant  disintegra- 
tion of  the  rock  above  (Fig.  12). 

The  moisture-laden  atmosphere  is  always  busy  producing 
destructive  changes  on  the  exposed  rocks.     Crack  open  any 


/  .,^«j 
^<? 


m 


.?.>•* 


-ii_ 


^    -<:''-! 
"'??'*■ 


.  « 


Fig.  12. — A  talus  at  foot  of  clifif  and  outwash  from  the  hills 


field  bowlder  and  you  will  see  a  layer  of  weathered  material 
on  its  outer  portion  that  crumbles  readily.  The  rock  piles, 
excavated  in  mining  or  quarrying,  show  nicely  the  results  of 
this  weathering.  The  great  angular  blocks  that  were  dumped  a 
decade  or  more  ago  are  crumbling  into  heaps  of  rock  fragments, 
many  of  them  sufficiently  disintegrated  to  make  coarse  soil 
where  weeds  and  some  trees  are  beginning  to  root.  This  process 
of  the  transformation  of  blocks  of  rock  into  soil  may  readily  be 
seen  on  the  dumps  of  the  local  quarries  or  along  the  line  of  the 


THE  CHANGING  FACE  OF  NATURE 


13 


Chicago  Drainage  Canal,  conveniently  reached  at  Willow  Springs, 
or  on  the  rock  dumps  of  the  coal  mines  near  Braiderwood,  on  the 
Chicago  &  Alton  Railroad. 

Wind  must  be  regarded  as  an  agent  of  land  destruction,  and 
a  transformer  of  the  landscape.  One  needs  only  spend  a  day  in 
the  Dunes  to  realize  its  efficiency,  if  that  day  be  a  windy  one. 
There  is  visible  evidence  that  the  wind  is  moving  the  sand;  the 


Fig.  13. — A  moving  dune  invading  a  swamp  and  burying  pines  and  junipers 
on  its  margin. 

air  is  full  of  it.  Close  to  the  ground  it  is  drifting  along  and 
strikes  one's  hand  or  face,  when  lying  down,  with  stinging  force. 
The  hills  of  sand  are  moving  inland  (Fig.  13)  covering  up  the 
forests,  invading  the  streams,  and  turning  them  from  their 
courses.  The  movement  of  the  great  dunes,  hills  of  sand 
hundreds  of  feet  high  and  thousands  of  feet  long  that  sweep 
along  like  snow  drifts,  is  quite  rapid.  The  steep  front  may 
advance  several  feet  a  year,  by  actual  measurement  from  stakes 


14 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


set  at  regular  intervals  to  serve  as  fixed  standards.     Forests  are 
covered,  killed,  and  uncovered. 

When  on  the  old  dunes,  covered  now  with  woods,  a  great 
tree  falls  and  so  exposes  the  loose  sand  again  to  the  wind,  or  when 
the  changing  contour  of  the  land  sets  the  wind  currents  against 
some  new  and  pooily  protected  spot,  a  great  hole  is  blown  out 
of  the  land  and  the  sand  is  carried  inland  to  be  deposited  in  some 
new  spot  as  a   moving  dune.     These   blow-outs  (Fig.  14)  are 


Fig.  14. — A  blow-out  in  the  dunes 

characteristic  features,  marked   with  the   wreckage  of  former 
forests. 

As  has  been  suggested  above,  these  agents  that  wear  away 
the  land  are  also  agencies  of  land  formation.  The  ocean,  whose 
waves  pound  the  shore  debris  into  sand  and  still  finer  mud, 
carries  this  material  by  its  undertow  and  currents  out  into  the 
quieter  portions  and  drops  it  offshore  in  sand  bars  and  mud 
banks.  These  deposits  accumulate  to  great  depths,  hundreds 
and  even  thousands  of  feet  in  thickness.  The  rivers  bring  down 
their  tons  of  material  to  add  to  the  accumulation.     Thus  the 


THE  CHANGING  FACE  OF  NATURE  15 

Mississippi  discharges  annually  into  the  Gulf  of  Mexico  as  much 
debris  worn  away  from  the  land  in  its  course  as  would  a  thousand 
cargo  ships  each  carrying  ten  thousand  tons.  Dip  a  pailful  of 
water  from  the  Des  Plaines  at  Riverside  when  the  spring  freshet 
is  on  or  from  the  Illinois  at  Starved  Rock;  let  the  suspended 
mud  settle,  collect  it,  dry  it,  and  then  weigh  it,  and  you  will  be 
surprised  to  see  how  much  soil  one  cubic  foot  of  water  is  carrying. 
Measure  the  width  of  the  stream,  its  average  depth,  and  its 
rate  of  flow  by  getting  the  distance  a  floating  chip  goes  in  Ave 
or  ten  minutes;  calculate  from  this  data  the  volume  of  water 
that  passes  in  an  hour's  time,  then  the  weight  of  sediment  it 
carries,  and  it  foots  up  an  incredible  amount.  All  the  streams 
that  flow  into  Lake  Michigan  are  ceaselessly  filling  in  the  lake. 
The  wave  action  along  its  shores  tends  to  make  it  wider,  but  also 
shallower  since  the  eroded  material  is  carried  out  to  settle  in  the 
quieter,  deeper  portions.  The  constant  necessity  of  dredging  out 
harbors  and  their  approaches  is  readily  understood  when  one 
appreciates  this  incessant  deposition. 

The  ultimate  fate  of  a  lake  or  pond  is  to  be  transformed  into 
land  as  it  is  filled  up  by  the  material  washed  into  it  from  the 
surrounding  hills  and  by  accumulating  plant  debris  (Fig.  15)^ 
Becoming  shallower,  water  weeds  and  rushes  grow  farther  and 
farther  out  in  it  until  it  transforms  into  a  marsh.  Even  then  the 
filling  does  not  cease,  for  each  year's  crop  of  marsh  grass  and 
water  weeds  piles  up  and,  only  partly  decomposing,  aft'ords  the 
following  year  a  slightly  higher  footing  for  the  next  crop.  Wolf 
Lake  and  Lake  Calumet  are  both  shallow  and  filling  rapidly. 
Already  many  of  their  bays  are  marsh  rather  than  pond  areas. 
Indeed,  along  the  margins  of  these  lakes  it  is  very  easy  to  trace 
all  stages  from  pond  to  prairie  land. 

The  river  builds  land  instead  of  eroding  it  wherever  its 
current  is  checked.  The  carrying  power  of  a  stream  depends 
on  its  rate  of  flow  and  its  volume.  The  swift  current  can  keep 
coarse  material  moving  that  is  deposited  when  the  movement  is 
sluggish.     When  the  stream  flows  into  pond  or  lake,  its  rate  of 


1 6  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Fig.  15. — A  filling  pond,  with  water  lilies  and  cat-tails  growing  in  profusion 


Fig.  16. — A  flood  plain  where  deposits  occur  during  overflow.     At  the  right 
the  bluff  marks  the  edge  of  the  flood  plain. 


THE  CHANGING  FACE  OF  NATURE  17 

flow  is  lessened,  in  consequence  of  which  a  bar  is  often  formed  at 
its  mouth  or  in  larger  streams,  a  delta.  Deposits  are  laid  down 
below  an  obstruction  like  a  bowlder  in  midstream.  While  the 
stream  cuts  on  the  outside  of  a  wide  curve  where  its  flow  is  rapid, 
it  deposits  on  the  inside  where  it  is  slow.  Often  the  spring 
freshets  raise  the  height  of  a  river  so  it  overflows  its  usual  channel. 
The  current  beyond  this  is  relatively  sluggish  so  that  over  the 
flood  plain  there  is  formed  a  deposit  of  mud  washed  from  the 
hills  upstream  (Fig.  16).  This  flood  plain  is  frequently  enriched 
by  this  annual  addition  of  humus,  so  that  river  bottoms  proverbi- 
ally have  good  soil. 

The  accumulated  soil  and  rock  debris  swept  from  a  continent 
by  the  various  agencies  of  erosion  and  transportation  deposited 
in  quiet  bays  or  ocean  deeps  gradually  transforms  to  rock  again, 
so  new  lands  are  formed  as  old  ones  are  destroyed.  When  exten- 
sive deposits  accumulate  offshore  or  in  the  deltas  of  great  rivers, 
the  very  weight  of  material  seems  to  cause  the  earth's  crust  to 
gradually  sink.  Thus  the  deposits  may  continue  to  accumulate, 
as  is  apparently  the  case  in  the  Gulf  of  Mexico,  until  they  become 
very  thick.  Then  the  lower  mud  layers,  pressed  upon  by  the 
thousands  of  feet  of  overlying  layers,  baked  by  the  heat  of  the 
interior,  since  they  are  ever  sinking  farther  from  the  surface, 
are  transformed  into  rock  in  a  w^ay  analogous  to  the  manner  in 
which  w^e  make  brick  or  artificial  stone,  by  compressing,  then 
heating  the  mud  or  clay.  So  sedimentary  rocks  have  formed, 
probably  are  forming  in  our  Great  Lakes  now.  Certainly  they 
have  so  formed  here  in  the  Chicago  region,  for  our  dominant 
bedrock,  the  limestone,  is  of  sedimentary  origin. 

Movements  of  the  earth's  crust  often  upheave  these  beds  of 
mud  transformed  to  rock,  so  adding  to  the  surface  of  the  land. 
The  outer  crust  of  the  earth  is  relatively  cool,  the  inner  portion 
of  the  earth  still  exceedingly  hot.  Like  any  hot  body  it  gradually 
cools,  and  cooling  shrinks;  so  it  tends  to  shrink  away  from  the 
already  cooled  crust.  This,  of  course,  can  never  actually  happen, 
for  the  heavy  crust  crumples  down  on  to  the  shrinking  central 


i8 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


portion  being  thrown  into  folds,  some  of  which  thrust  the  rock 
layers  up,  some  down  (Fig.  17).  These  changes  in  level  of  the 
earth's  crust  sometimes  are  so  sudden  as  to  cause  an  earthquake, 
but  usually  they  are  so  gradual  as  to  be  imperceptible  except  as 
comparisons  are  made  at  long  intervals.  The  northern  shores  of 
'Lake  Michigan  are  now  rising — have  risen  on  the  west  side  of 
the  lake  two  feet  or  so  in  a  generation.  We  know  that  the  lime- 
stone that  makes  up  the  bedrock  of  the  Chicago  region,  now 


Fig.  17. — Up-arched  rock  strata 


dry  land,  was  formed  under  the  surface  of  the  ocean,  for 
it  contains  fossil  remains  of  animals  and  plants,  shellfish,  and 
seaweed  that  live  only  in  the  sea.  We  shall  see  evidence  of 
many  changes  in  level  in  our  region. 

Along  the  Atlantic  Coast  there  is  evidence  of  a  sinking  shore. 
Stump  lands  along  the  coast  are  now  completely  under  water. 
The  Hudson  River  Valley  is  shown  by  soundings  to  continue 
well  out  to  sea,  its  lower  end  having  been  ''drowned"  as  the 
land  sank  there.  Along  the  western  coast  of  South  America 
coral  reefs  are  found  well  up  on  the  sides  of   the  mountains. 


THE  CHANGING  FACE  OF  NATURE 


19 


Fig.  18. — The  edge  of  an  old  lava  outflow,  now  basalt,  covering  a  wide  area 


Fig.  19. — Glacial  moraine  in  the  foreground  deposited  by  the  glacier,  right 
and  rear. 


20         A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

Evidently  they  must  have  formed  below  sea-level,  and  the 
mountains  have  been  reared  since  then. 

Volcanoes  are  another  agency  of  land  formation.  The  lava 
welling  from  their  craters  or  from  cracks  in  the  earth  pours  out 
in  great  sheets  (Fig.  i8)  w^hile  molten,  only  to  harden  as  it 
cools  into  beds  of  rock.  Fortunately  for  our  peace  of  mind  no 
volcanoes  exist  in  the  Chicago  area,  though  we  do  have  lavas, 
like  the  granite  and  greenstone  glacial  bowlders  that  have  been 
transported  by  the  ice  from  the  old  lava  beds  to  the  north  of  us 
into  our  region. 

The  glacier  builds  as  wxll  as  destroys.  The  ice  mass  incorpor- 
ates into  itself  the  rock  fragments  torn  from  its  bed  and  sides,  so 
the  onward  moving  river  of  ice  is  loaded  with  debris  and  abraded 
material.  At  some  place  it  encounters  a  temperature  sufficiently 
high  to  melt  it  as  rapidly  as  it  pushes  forward.  Here  it  must 
drop  its  load  of  rock  powder  and  rock  fragments  and  so  it 
forms  a  great  pile  along  its  front,  a  terminal  moraine  (Fig.  19). 
Streams  of  water  made  by  the  melting  ice  pour  out  of  gaps  in  the 
moraine  on  to  the  country  beyond,  carrying  gravel  and  sand  that 
are  deposited  in  great  fans  or  along  the  valley,  if  the  outwashing 
stream  follows  such,  in  elongated  heaps  or  valley  trains.  These 
and  other  forms  of  deposit  characteristic  of  the  glacier  are  found 
about  Chicago  as  will  appear  in  a  later  chapter. 


CHAPTER  II 
THE  WORLD  IN  THE  MAKING 

HE  world  passed  through  a  long  period 
of  development  before  there  were  any 
oceans  or  rivers  or  atmosphere  upon  it  to 
serve  as  agents  of  erosion  or  deposition. 
The  earth  on  which  we  live  is  one  of 
several  similar  bodies  called  planets  that 
move  about  the  sun.  These  planets,  in 
order  from  the  sun  outward,  are  Mercury, 
Venus,  Earth,  Mars,  Jupiter,  Saturn,  Uranus,  and  Neptune. 
Around  many  of  these  planets  as  centers  there  are  other  smaller 
bodies  known  as  moons.  The  earth  has  one  attendant  moon, 
Jupiter  four,  Saturn  ten.  Planets  and  moons  appear  bright  when 
seen  from  the  earth,  shining  by  the  reflected  light  of  the  sun.  The 
planets  look  like  stars  to  the  naked  eye ;  the  ones  near  our  earth  are 
very  bright  and  are  familiar  as  evening  and  morning  stars.  Our 
sun,  on  the  other  hand,  shines  because  its  substance  is  so  intensely 
hot  that  it  is  perpetually  emitting  light.  It  is  a  true  star  and  not  a 
very  large  one  either,  but  it  is  so  near  our  earth,  comparatively 
speaking,  that  its  light  and  heat  seem  much  greater  to  us  than  that 
of  much  larger  suns  or  stars  that  are  very  far  away.  The  diam- 
eter of  one  of  the  stars  in  the  constellation  Orion,  Betelgeuse  by 
name,  recently  measured  by  a  newly  devised  instrument,  is  some 
three  hundred  times  that  of  the  sun.  Sun  and  planets,  moons, 
and  some  still  smaller  bodies  that  revolve  about  the  sun  together 
make  up  our  solar  system.  Probably  the  other  stars  are  also 
centers  of  planetary  systems. 

The  eye  unaided  counts  four  or  five  thousand  stars,  but  the 
telescope  enables  us  to  locate  hundreds  of  thousands,  and  each 
new  telescope  more  powerful  than  its  predecessors  adds  to  the 


21 


2  2  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

number.  These  stars  are  themselves  not  fixed  but  are  moving 
through  space  with  terrific  speed.  Our  sun,  carrying  the  other 
bodies  of  the  solar  system  along  with  it,  is  swinging  along  in 
its  orbit  at  the  rate  of  some  twelve  miles  per  second,  but 
neither  the  size  of  its  orbits  nor  its  center  has  as  yet  been 
determined. 

What  a  tremendous  tangle  of  pathways  is  woven  by  these 
onrushing  suns,  their  circHng  planets,  and  the  moons  that  move 
about  them.  The  criss-crossing  railroads  of  our  countr}^  present 
a  simple  maze  in  comparison.  What  a  splendid  opportunity  for 
an  occasional  smash-up  if  two  of  the  suns  or  two  of  the  yet  more 
numerous  dark  bodies  should  dispute  with  each  other  the  right 
of  way  at  some  crossing  of  their  pathways.  Astronomers  tell 
us  that  this  sort  of  thing  occasionally  happens,  resulting  in  the 
blazing  out  of  a  new  star  as  two  of  the  dark  bodies  rush  head- 
long together,  generating  thereby  enough  heat  to  change  their 
substance  into  a  cloud  of  incandescent  material. 

Even  more  frequently  two  bodies  will  come  close  enough 
together  as  they  rush  by  each  other  to  disrupt  each  other,  each 
being  torn  more  or  less  to  pieces  by  opposing  forces,  the  momen- 
tum of  its  own  precipitate  motion  in  its  pathway,  and  the  attrac- 
tion of  the  other  body.  It  is  from  some  such  wreckage  that  our 
solar  system  is  supposed  to  have  originated.  The  largest 
remaining  fragment  or  coterie  of  fragments  dominated  the  rest 
and  became  the  nucleus  of  reorganization,  the  central  sun. 
About  it,  as  a  resultant  of  their  original  impetus  and  the  force 
of  mutual  attraction,  the  smaller  fragments  revolved,  drawing  in 
turn  about  them  the  still  smaller  ones. 

Our  earth  began,  then,  as  a  knot  of  dense  material  in  the 
cloud  of  fragmented  material.  By  its  attraction  it  drew  to 
itself  the  smaller  bits  about  it  and  they  moved  toward  it  with 
increasing  momentum,  finally  smashing  down  on  to  its  surface. 
Gradually  the  earth  nucleus  grew  as  it  accumulated  these  tiny 
revolving  bodies,  the  planetesimals,  whose  pathways  brought 
them  within  reach  of  its  quite  powerful  attraction. 


THE  WORLD  IN  THE  MAKING  23 

Naturally  the  great  central  mass,  our  sun,  grew  even  more 
rapidly,  for  its  pull  was  in  proportion  to  its  mass,  so  that  it 
reached  out  in  its  might  to  draw  to  itself  many  times  the 
number  of  planetesimals  that  the  relatively  small  earth  could 
reach. 

This  process  has  been  going  on  for  long  ages  and  still  goes  on. 
The  earth  comes  near  some  small  mass  moving  in  its  orbit  and 
by  its  tremendous  gravity  pulls  it  toward  itself.  It  rushes 
toward  the  earth,  passes  through  the  outer  air  with  such  ve- 
locity that  the  friction  heats  it  intensely;  it  continues  to  fall  a 
burning  mass  and  usually  is  consumed,  but  at  times  may  reach 
the  earth's  surface.  These  bodies  we  call  meteors  or,  improperly, 
falling  stars ;  if  a  star  should  hit  the  earth  we  would  not  live  to  tell 
the  tale.  H.  A.  Newton  estimates  from  his  careful  observations 
that  sixteen  millions  of  these  meteorites  enter  our  atmosphere 
every  twenty-four  hours.  According  to  William  H.  Pickering 
they  add  over  one  hundred  tons  to  the  earth  each  year.  "By 
far  the  most  of  them  are  so  minute  that  they  are  consumed  before 
they  reach  the  ground,  though  about  one  thousand  do  that  every 
year,  some  of  them  of  considerable  size."  The  meteorite  that 
Peary  brought  down  from  the  North  now  in  the  American 
Museum  of  Natural  History,  New  York,  weighs  more  than  thirty- 
seven  tons.     There  have  probably  been  much  larger  ones. 

Not  far  from  Flagstaff,  Arizona,  is  a  remarkable  crater-like  depression 
[Fig.  20].  The  rim  of  it,  rising  about  140  feet  above  the  plain,  can  be  seen 
from  the  railroad,  passing  Canon  Diablo.  The  depression  has  a  diameter 
of  about  three-quarters  of  a  mile,  and  the  bottom  is  500  feet  below  the  top 
of  the  rim,  350  feet  below  the  surface  of  the  plain.  No  one  can  look  upon 
this  remarkable  phenomenon  without  thinking  of  the  craters  of  the  moon. 
But  there  are  no  signs  of  volcanic  action  ever  having  taken  place  in  this 
region;  the  thing  is  out  of  the  question.  The  rim  piled  around  the  crater 
has  not  come  from  the  interior  of  the  earth,  but  is  composed  of  sandstone, 
which  in  some  way  has  been  lifted  above  the  plain.  Some  of  the  great 
masses  of  this  sandstone  have  apparently  been  highly  heated  and  crystal- 
lized, but  most  of  the  rock  has  been  crushed  and  shattered.  The  whole 
neighborhood  is  sown  with  meteors. 


24  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Fig.  20. — Portion  of  so-called  "crater"  of  Canon  Diablo,  probably  made  by 
the  falling  of  a  great  meteorite. 


Fig,  21. — A  spiral  nebula  with  centers  of  condensation,  the  great  central  one 
giving  rise  to  a  sun,  the  others  to  planets  and  satellites.  Photo  by  jMount 
Wilson  Observatory,  _-. 

fiOKRrr  UBRARY 


n.  C.  State  College 


THE  WORLD  IN  THE  MAKING  25 

Without  much  question  the  depression  and  surrounding  rim 
mark  the  spot  where  some  huge  meteoric  mass  has  plunged  into 
the^earth.     Lunar  ''craters"  likely  have  had  a  similar  origin. 

So  according  to  the  planetesimal  hypothesis  our  earth  can 
trace  her  history  back  to  the  time  when  she  was  one  of  the  larger 
knots  of  matter  in  the  arm  of  a  spiral  nebula  (Fig.  21).  Because 
of  the  original  size  of  this  knot  and  the  abundant  meteoric 
material  her  changing  orbit  brought  her  into,  she  grew  apace  as 
falling  planetesimals  were  added  to  her  bulk,  and  now  she  is 
the  fifth  largest  of  the  planets  in  our  solar  system.  Jupiter,  the 
largest,  is  more  than  thirteen  hundred  times  the  size  of  our  earth. 
Saturn,  Neptune,  and  Uranus  are  also  larger.  Venus,  Mars,  and 
Mercury  are  smaller. 

As  the  earth  thus  grew  in  size  it  also  became  hot.  The 
succession  of  blows  delivered  by  the  hail  of  planetesimals  gen- 
erated heat,  as  the  anvil  becomes  hot  under  repeated  hammer 
strokes  or  a  nailhead  is  heated  when  the  nail  is  being  driven  into 
hard  wood.  This  heat  was  superficial  and  quickly  radiated. 
The  central  portion  of  the  earth  was,  however,  constantly  being 
pressed  upon  by  the  overlying  accumulating  mass.  As  the  earth 
grew  constantly  by  accession  the  central  portion  was  condensed 
more  and  more.  We  are  all  familiar  with  the  fact  that  heat 
makes  things  expand.  The  mercury  in  the  thermometer  bulb 
expands  more  than  the  glass  and  so  rises  in  the  tube  with 
increased  heat.  The  opposite  of  this  is  also  true :  as  substances 
condense  heat  is  liberated;  so  the  earth's  interior  became  heated. 
The  condensation  of  the  central  mass  also  caused  molecule  to 
rub  against  molecule  as  crushing  went  on  and  so  added  to  the 
central  heat.  The  pressure  was  so  great  near  the  center  that 
the  rock  material  could  not  actually  melt.  But  nearer  the 
surface,  especially  where  up-arching  of  the  crust  reheved  the 
pressure  temporarily,  the  rock  material  melted,  oozed  up  toward 
the  surface,  infiltrated  between  the  piled-up  chunks  and  dust, 
cementing  these  into  a  solid  mass  as  the  molten  material  cooled. 
Thus  formed,  likely,  the  early  igneous  rocks. 


26 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


If  we  should  make  a«n  ideal  section  of  the  earth  at  this  early 
stage  (Fig.  22)  the  surface  layer  would  be  very  irregular,  due  to 
the  indiscriminate  infalling  of  planetesimals.  The  next  zone 
would  be  ver}'  porous,  similar  to  the  contents  ©f  a  basket  filled 
with  large  potatoes,  only  the  fragments  would  be  vastly  larger, 

more  or  less  cemented 
with  lava.  The  zone 
below  would  be  less 
porous,  as  the  planet- 
esimal  matter  would  be 
pressed  together  by  the 
weight  of  the  zone  on 
top  of  it.  The  central 
core  of  the  planet  would 
be  very  compact,  due  to 
the  pressure  of  the  zones 
above  it.  The  diagram 
shows  the  later  rock 
layers  on  the  outside  of 
this  early  earth. 

]\Ieanwhile  the  young 
earth,  growing,  reached 
a  stage  when  it  doubtless 
could  hold  the  begin- 
nings of  an  atmosphere. 
As  the  earth's  gravity 
gradually  increased  it 
would  first  be  able  to 
hold  the  gases  that  are  heaviest  and  least  volatile.  Carbon 
dioxide  is  the  heaviest  of  all  the  gases  that  make  up  our  atmos- 
phere. Ox}^gen  is  next  in  weight;  then  nitrogen,  water  vapor, 
and  hydrogen  follow  in  succession.  The  earth  is  still  not  large 
enough  to  hold  much  hydrogen. 

When  the  earth  had  reached  such  a  size  as  enabled  it  to  hold 
water  vapor  the  atmosphere  was  piled  high  with  clouds.     Rains 


Fig.  22. — Diagrammatic  section  of  the  earth 


THE  WORLD  IN  THE  MAKING  27 

poured  upon  the  surface  only  to  evaporate  promptly,  it  was  so 
hot.  Gradually  the  surface  cooled  sufficiently  so  water  could 
remain.  Then  the  little  drops  of  water  congregated  in  the 
spaces  between  the  rocks  in  the  upper  zone.  Gradually  these 
cracks  were  filled  with  water  and  the  water  overflowed  and 
formed  little  pools.  The  pools  grew  into  lakes,  and  the  lakes 
joined  each  other  and  formed  oceans. 

The  torrential  rains  washed  the  rock  not  covered  with  water 
and  formed  rivers  that  carried  the  sediment  down  and  deposited 
it  on  the  rocks  under  the  oceans.  This  continued  long  ages. 
In  this  way  the  ocean  floors  had  the  weight  of  the  waters  upon 
them  and  the  added  weight  of  the  deposited  material.  This 
made  them  sink,  deepening  the  ocean  basins  and  pushing  up  the 
land  masses,  making  the  continental  platforms  higher. 

Now,  no  sooner  were  the  continental  areas  raised  above  the 
ocean  level  than  all  the  agencies  of  erosion  were  turned  loose 
upon  them.  The  waves  beat  upon  the  land,  the  rain  pounded 
it,  the  brooks  and  rivers  furrowed  it,  underground  waters  honey- 
combed it,  in  time  snowfields  thrust  out  huge  ice  sheets  to  grind 
down  the  hills  and  deepen  the  valleys,  frost  shattered  the  rock 
cliffs,  the  gases  of  the  air  united  with  the  rocks  to  alter  them  into 
soft  materials  easily  eroded,  earthquakes  rent  the  land,  the 
sand-laden  winds,  the  chemical  action  of  organisms  growing  on 
the  rocks — these  all  aided  in  the  rock  disintegration  and  soil 
formation  and  prepared  for  the  transportation  of  materials  by 
these  same  agencies  to  lower  levels  and  finally  to  the  lakes  and 
seas. 

This  process  of  transportation  was  as  incessant  as  erosion. 
Ponds  and  lakes  constantly  filled  up  with  the  wash  from  the 
uplands.  Rivers  carried  immense  loads  of  sediment  into  the 
oceans.  The  United  States  Geological  Survey  estimates  that 
the  material  washed  from  the  surface  of  this  country  and  carried 
off  by  the  rivers  annually  amounts  to  over  one-quarter  billion 
tons.  And  so  the  material  that  was  originally  rock  and  had 
been  eroded,  transported,  and  deposited  began  to  fonn  rock 


28  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

again.  The  deeper  layers  of  those  vast  accumulations  of  sedi- 
ment in  ocean  deeps,  in  inland  seas,  and  great  bays  were  under 
the  terrific  pressure  of  the  overlying  layers  and  fathoms  of 
ocean  waters.  They  became  intensely  heated,  for  they  were  far 
enough  below  the  surface  to  feel  the  heat  of  the  earth's  interior, 
retained  by  the  blanket  of  overlying  layers.  So  they  were  trans- 
formed into  rock. 

These  beds  raised  the  temperature  of  the  older  underlying 
rocks  almost  to  the  point  of  fusion,  establishing  a  line  of  weak- 
ness here  so  that  as  the  crust  movements,  due  to  unequal  shrink- 
age, occurred  these  areas  of  weakness  were  readily  upheaved,  the 
sedimentary  rock  strata  were  arched,  sometimes  crumpled,  and 
thrown  up  above  the  sea. 

Similarly  all  over  the  earth  the  sedimentary^  rocks,  formed  in 
successive  geological  ages,  have  been  upheaved  and  occasionally 
exposed  to  our  inspection.  These  rocks  often  contain  fossils, 
the  remains  of  animals,  and  plants  that  Hved  in  past  geological 
times.  Such  animals  and  plants  Hving  in  the  water  or  washed 
from  the  land  into  the  streams  possibly  by  spring  freshets  were 
carried  seaward  and  deposited  with  other  debris,  with  sand  and 
silt  in  the  great  mud  banks  in  lakes  and  oceans.  These,  by  the 
process  outHned  above,  were  changed  to  stone,  and  so  the 
bones  or  shells  of  animals,  the  bark,  fruits,  and  even  leaves  of 
plants  have  been  preserved,  gradually  assuming  a  stony  texture 
(Fig.  34,  36).  Or  if  the  softer  parts  rotted  away,  the  cavity 
left  filled  in  with  rock  in  time  and  so  made  a  cast  of  the  organism 
showing  to  this  day  all  the  delicate  details  of  the  original.  These 
fossil  remains,  when  carefully  studied,  yield  an  interesting  history 
of  Hving  things  upon  the  earth.  The  science  which  deals  with 
these  fossil  remains  is  paleontology,  a  special  department  of 
geology. 

Our  western  plains  are,  in  places,  particularly  rich  in  the 
fossil  remains  of  some  of  the  great  vertebrates.  Scarcely  a 
summer  passes  that  scientific  expeditions  are  not  organized  to 
go  out  and  explore  these  regions  and   find  the  fossils.     The 


THE  WORLD  IN  THE  MAKING  29 

scientists  of  the  expedition  then  skilfully  remove  them  from  the 
rock,  often  spending  days  in  chiseling  away  the  rock  from  around 
the  cast  of  some  old  bones  or  in  cementing  together  the  more 
or  less  cracked  remains  so  they  may  be  transported  safely.  They 
are  then  shipped  to  the  great  museums,  where  they  can  be 
leisurely  set  up  and  carefully  studied. 

The  paleontological  record  is  at  no  place  on  the  earth  com- 
plete. It  would  seem  at  first  thought  as  if  in  digging  deep  mines 
we  might  hope  to  begin  excavations  in  rocks  of  recent  formations 
and  then  dig  down  deeper  and  deeper  through  successively  older 
rocks.  So  we  could  find  animal  and  plant  remains  that  would 
enable  us  to  reconstruct  readily  the  history  of  living  organisms. 
But  the  task  is  not  so  simple. 

In  an  ideal  section  of  the  earth's  crust  (using  the  term  in 
the  sense  of  the  outer  accessible  layer)  we  should  find  the  oldest 
rocks  deep  down,  then  later  and  later  rocks  in  successive  layers 
upon  them,  and  finally  the  very  recent  rocks  at  the  surface  of 
the  earth.  Such  a  condition  is  purely  ideal;  it  exists  only  in 
the  mind  of  the  geologist.  It  is  fortunate  that  this  is  so,  for  if  the 
oldest  rocks  were  always  buried  miles  and  miles  deep  under  the 
layers  of  later  formations  we  could  know  nothing  about  them.  As 
it  is  they  have  often  been  upheaved  and  recent  rocks  have  been 
eroded  off  from  them.  The  rock  layers,  by  violent  upheaval, 
have  been  turned  upside  down  in  places  so  that  the  older  rocks 
are  on  top. 

Whenever  the  sedimentary  rocks  with  their  fossil  remains  have 
been  upheaved  above  the  ocean  level,  the  process  of  deposition 
has  been  thereby  stopped  and  so  the  fossil  record  has  been  inter- 
rupted. Moreover,  no  sooner  were  these  rocks  lifted  above  the 
ocean  than  erosion  began,  and  the  historical  record  that  had  been 
made  was  rapidly  destroyed. 

Thus  the  paleontologist  reads  the  history  of  life  upon  the 
earth  from  a  great  book  whose  leaves  are  the  rock  strata  on  which, 
in  fossil  characters,  the  record  is  inscribed.  Just  as  ancient 
human  history  must  be  patched  together  by  the  experts  from 


30         A  NATURALIST  IN  TEE  GREAT  LAKES  REGION 

fragmentary  bits,  a  clay  tablet  dug  up  from  some  old  ruin  in 
the  Euphrates  Valley,  some  bit  of  papyrus  taken  from  an 
Eg}^tian  pyramid,  some  roll  unearthed  from  ash-covered 
Herculaneum,  so  must  this  geological  record  be  constructed 
out  of  authentic  scraps  of  information  gathered  from  the  rocks 
of  the  several  continents.  Much  of  the  record  is  covered  up 
under  layers  of  soil  and  is  inaccessible.  Only  in  the  quarry,  the 
mine,  the  chance  exposure  of  rock  strata  by  railroad  cut,  the  river 
gorge,  or  mountain  ledge  can  the  explorer  find  the  fossil  remains. 
These  give  opportunity  for  the  study  of  a  mere  fraction  of  the 
whole  record.  It  is  surprising  that  the  geologist  has  been  so 
successful  in  reconstructing  the  history^  of  hfe  upon  the  earth  in 
the  face  of  such  difhculties. 

The  historian  divides  the  time  of  the  enactment  of  human 
histor}^  into  the  modern  age,  the  medieval,  the  ancient,  back 
still  farther,  an  age  of  myth  and  folklore  in  which  events  are 
dimly  seen,  and  finally  a  prehistoric  age  when  the  happenings 
must  be  matters  largely  of  conjecture.  So  the  geologist  sub- 
divides the  history  which  he  reads  in  the  strata  of  the  earth's 
crust  into  the  Cenozoic,  ^lesozoic.  Paleozoic,  Proterozoic,  and 
Archaeozoic  eras.  Then  just  as  man  subdivides  historical  ages 
into  smaller  periods,  as  for  instance  the  age  of  ancient  history, 
into  the  Babylonian  period,  the  Egyptian  period,  the  Grecian 
and  Roman  periods,  so  the  geological  eras  are  subdivided.  The 
tabulation  at  the  end  of  the  chapter  will  show  the  main  divisions 
and  subdivisions  of  geological  time  and  will  serve  as  reference 
to  place  the  events  about  to  be  recorded.  It  will  also  facilitate 
the  reading  of  the  bulletins  in  the  bibliography  at  the  end  of  the 
book. 

The  different  rock  strata  are  referred  by  the  experts  to  various 
of  these  time  divisions  according  to  the  time  of  their  formation. 
Thus  we  speak  of  carboniferous  rocks — those  that  were  deposited 
during  the  Carboniferous  period.  The  relative  age  of  any  rock 
layer  is  determined  by  finding  what  rocks  are  below  it,  what 
are  above  it,  and  by  the  character  of  the  fossils  it  contains. 


THE  WORLD  IN  THE  MAKING  31 

Under  the  eras,  periods,  and  their  subdivisions  are  given  at 
the  left  the  names  of  the  better-known  formations  belonging  to 
each,  mostly  those  of  the  eastern  states,  while  at  the  right  are 
those  of  Illinois  and  adjacent  regions.  Unless  the  names  are 
identical,  those  on  the  same  line  in  the  two  series  are  not  to  be 
taken  as  necessarily  equivalent. 

Cenozoic  Era 

Quaternary 

Recent  period 

Pleistocene  period 
Tertiary 

Pliocene  period 

Miocene  period 

Oligocene  period 

Eocene  period 

Mesozoic  Era 

Cretaceous  period 
Comanchean  period 
Jurassic  period 
Triassic  period 

Paleozoic  Era 

Permian  period 
Upper  Permian 
Rustler 

Castile  gypsum 
Lower  Permian 
(Brazos  or  Oklahomian) 
Delaware  Mountain 
Dunkard      shales,      sand- 
stones,   and    limestones 
Pennsylvanian  period 

Monongahela  shales,  sand- 
stones, and  limestones 
Conemaugh   shales,    sand-      McLeansboro  series,  including  clay, 
stones,  and  limestones  limestone,   slate,   sandstone,   and 

the  LaSalle  first-vein  coal,   also 
known  as  Streator  No.  7 
Allegheny     shales,     sand-      Carbondale  series,  clay,  limestone, 
stones,  and  limestones  slate,     sandstone,     and     LaSalle 


32  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Pottsville  sandstone  or  con- 
glomerate     (Millstone 
grit) 
Mississippi  period 
Upper  Mississippian 
(Chester  series) 

Grand  Rapids  series 
in  ]\Iichigan 


Marshall  series  in  IVIichigan 


Lower  ]\Iississippian 

(lowan  series) 
Meramce 

St.  Genevieve  limestone 

St.  Louis  limestone 

Spergen  sandstone 

Warsaw 
Osage 

Keokuk  limestone 

Burlington  limestone 

Fern  Glenn  limestone 
Kinderhook 

Chautauquan  limestone 

Hannibal  shale 

Sulphur  Springs  sandstone 

Louisiana  limestone 


second-  (Springfield  No.  5)  and 
third-vein  (LaSalle  No.  2)  coals, 
the  latter  just  above  the  Potts- 
ville series,  including  clays  and 
sandstone 


Typically  exposed  in  southern  Illi- 
nois 
Kincaid  limestone 
Degonia  sandstone 
Clare  limestone 
Palestine  sandstone 
IMenard  limestone 
Waltersburg  sandstone 
\'ienna  limestone 
Tar  Springs  sandstone 
Glen  Dean  limestone 
Hardensburg  sandstone 
Golconda  limestone 
Cypress  sandstone 
Paint  Creek  limestone 
Yankeetown  formation 
Bethel  sandstone 
Renault  limestone 
Aux  Vases  sandstone 


Names  of  formations  are  for  the  most 
part  the  same  in  the  Central  West 


THE  WORLD  IN  THE  MAKING 


33 


Devonian  period 

Upper  Devonian 
Chautauquan  series 
Catskill  sandstone 
Chemung   sandstone   or 
shale 

Senecan  series 

Portage     sandstone     or 

shale 
Genessee  shale 
Tully  limestone 

Middle  Devonian 
Erian  series 
Hamilton  shale 
Marcellus  shale 

Ulsterian  series 

Onondaga  limestone 
Schoharie  grit 

Lower  Devonian 
Oriskanian  series 
Esopus  grit 
Oriskany  sandstone 

Helderbergian  series 
Becraft  limestone 
New  Scotland  limestone 
Coeymans  limestone 

Silurian  period 

Upper  Silurian  (Cayugan) 
Manlius  limestone 
Rondout  limestone 
Cobbleskill  limestone 
Salina  beds 

Middle  Silurian  (Niagara) 
Guelph  dolomite 
Lockport  limestone 


Rochester  shale 
Clinton  beds 


Mountain  Glenn  shale 


Alto  formation 


Lingle  limestone 
Misenheimer  shale 

Grandtower  limestone 
Dutch  Creek  sandstone 
Clear  Creek  chert 


Backbone  limestone 
Bailey  limestone 


Monroe  series,  Mich. 


Guelph  dolomite 
Reef  limestone 
Upper  coral  beds 
Lower  coral  beds 
Sexton  Creek 
Edgewood 


34 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Lower  Silurian  (Oswegan) 

Brassfield  sandstone 

Medina  sandstone 

Edge  wood  limestone 

Tuscarora 

Cataract  sandstone  or  shale 

Becksie  limestone 

Ordovician  period 

Upper    Ordovician    (Cincin- 
natian) 
Garoche 
Richmond  limestone 

Mayville  or  Loraine 
Eder  or  Utica  shale 

Middle    Ordovician    (Cham- 
plainian) 
Collingwood  limestone 
Trenton  limestone 
Black  River  dolomite 
Lowville  limestone 
Chazy  limestone 
Stones  River  limestone 
St.  Peter  sandstone 

Lower  Ordovician  (Canadian) 
Fort  Cassin  dolomite 
Beekmantown    or    Prairie 

du  Chien  dolomite 
Oneota  limestone 
Madison  sandstone 
Mendota  limestone 
The  last  three  are  possibly 
to  be  put  in  a  separate 
period,  the  Ozarkian 

Cambrian  period 

Upper  Cambrian  (Croixian) 

mostly  limestones 
Middle  Cambrian  (Acadian) 

mostly  limestones 
Lower  Cambrian  (Wauco- 
bian) 


Girardeau 


Richmond  shale  and  shaly  limestone 
(Maquoketa) 


Kimmeswick  and  Platten 
Galena  limestone 
Platteville  limestone 


St.  Peter  sandstone 

Shakopee  dolomite,  cement  rock,  and 

sandstone 
New  Richmond  sandstone 
Oneota  dolomite 
Jordan  and  Madison  sandstone 
St.  Lawrence  dolomite 


Franconia  glauconitic  sandstone 
Potsdam  (Lake  Superior  sandstone) 


Dresbach  shale  and  sandstone 
Lowest  sandstone 


THE  WORLD  IN  THE  MAKING  35 

pROTEROzoic  Era 

The  chief  rock  systems  in  this  era  in  the  Great  Lakes  region  are  in 
northern  Michigan,  Wisconsin,  and  Minnesota.  In  northern  Michigan 
they  are  as  follows: 

Upper  Ke  ween  a  wan 
Freda  sandstone 
Nonesuch  shale 
Outer  conglomerate 

Lower  Keweenawan 
.  Lake  shore  trap  (basic  lava) 
Great  conglomerate 
Eagle   River  and   Ashbed 

group   (acid  lava  intru- 

sives) 
Mesnard  epidote 
Central  mine  group  (basic 

lavas) 
Conglomerate    (acid    lava 

intrusives) 
Bohemia    Range     (mostly 

basic  lavas) 

Upper  Huronian 

Clarksburg  formation 

Michigamme  slate  anri 
schist 

Goodrich  formation  (mostly 
quartzite  and  conglom- 
erate) 

Middle  Huronian 
Presque  Isle  granite 
Quinnisec  schist 
Tyler  and  Hanbury  forma- 
tions 
Negaunee,     Vulcan,      and 

Ironwood  formations 
Ajibik,   Siamo,  and  Palms 

formations 
Hemlock  formation  (basic 

lavas) 
Kona,  Randville,  and  Bad 

River  formations 
Mesnard,     Sturgeon,     and 

Sunday     formations 

(mostly  quartzite) 

Archaeozoic  Era 
Laurentian 
Keewatin 


CHAPTER  III 


THE  STORY  OF  OUR  ROCK  FOUNDATION 


$i. 


HE  rock  immediately  underlying  the  soil 
in  the  Chicago  area  is  the  Niagara  lime- 
stone.    It  has  a  thickness  of  250-400 
feet.    It  is  exposed  in  many  places  about 
the  city  as  in  the  quarries  at  Stony  Island, 
Thornton,  Hawthorne,  Elmhurst,  on  the 
Chicago   &   North    Western   Railway; 
AlcCook,  on  the  Atchison,  Topeka  & 
Santa  Fe  Railway;    and  Lockport,  on  the  Chicago  &  Alton 
Railroad.     There  are  mile-long  heaps  of  it  beside  the  drainage 
canal  from  which  it  was  excavated  from  Willow  Springs  to  Lock- 
port,  and  also  beside  the  branch  ^anal  from  Blue  Island  to  the 
Sag.     At  Lockport  the  rock  comes  to  the  surface  and  forms  the 
bluffs  bordering  the  Desplaines  River  Valley  on  the  south,  and 
there  are  similar  bluffs  on  the  north  side  of  the  valley  at  Lyons. 
As  a  rule  the  strata  of  the  limestone  are  approximately  hori- 
zontal, dipping  slightly  to  the  south.     But  at  Stony  Island  they 
are  sharply  inclined  (Fig.  23)  and  that  in  opposite  directions  on 
the  two  sides  of  the  present  low  ridge,  showing  that  this  eleva- 
tion is  the  eroded  remnant  of  what  was  once  a  mountain  fold  of 
no  mean  height.     Similar  folds  of  the  strata  on  a  smaller  scale 
are  seen  in  many  of  the  quarries. 

Below  the  Niagara  limestone  occurs  a  succession  of  rocks 
which  in  a  deep  boring  at  Lockport  were  disclosed  as  shown  in 
the  accompanying  diagram  (Fig.  24).  Other  similar  borings 
have  given  like  results.  Presumably  if  the  drill  had  gone  deeper  it 
would  have  encountered  the  still  older  rocks  of  the  Proterozoic  era 
and  then  the  complex  of  the  Archaeozoic.  The  history  of  the  for- 
mation of  these  rocks  of  our  immediate  vicinity  is  most  interesting. 

36 


THE  STORY  OF  OUR  ROCK  FOUNDATION 


37 


Fig.  23. — The  east  and  west  quarries  on  Stony  Island.     Note  the  strata  dip 
in  opposite  directions. 


38 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


>■     Sandstones,  limy  shales,  limestones  and  coal. 


< 
I— I 

u 

l-H 
> 

o 
p 
pj 
o 


< 


\    II     I   -r-r 


,1    .1    ,1 


I     I     I    ~7'n' 


Limestone  and  shales. 

■*  Below  this  level  are  the  rock  strata  of  the  Chicago  area  as  revealed 
in  a  well  bored  at  Lockport  (after  Alden,  U.S.  Geological  Survey). 
Above  strata  found  to  south  and  east;  the  Devonian  is  slightly 
represented  at  Chicago. 

>     Niagaran,  dolomitic  limestone 230  ft. 


Richmond  (Cincinnati)  shale no  ft. 


>     Galena-Platteville  (Trenton)  limestone 300  ft. 


>     St.  Peter  sandstone .   210  ft. 


>    Lower  Magnesian  formation 395  ft. 

Dolomitic  limestone,  red  marl,  and  shale,  or  shaly  limestones. 


>    Potsdam  formation 

Sandstone,  red  marl,  and  shale  or  shaly  limestones. 


686  ft. 


Fig.  24.— Diagram  of  strata  in  the  Chicago  region 


THE  STORY  OF  OUR  ROCK  FOUNDATION 


39 


Concerning  the  earliest  rocks  that  made  up  the  outer  cool 
portion  or  crust  of  our  earth  we  know  nothing  except  by  inference, 
for  they  are  nowhere  subject  to  observation.  Probably  they 
were  lavas  that  had  outflowed  from  the  deeper  layers  on  to  the 
surface,  forming  not  only 'what  lands  there  were,  but  also  the 
bottoms  of  the  seas  and  oceans.     These  rocks  were  attacked  by 


Fig.  25. — Basaltic  dyke  intrusive  in  granite,  the  latter  lichen-covered,  south 
shore  of  Partridge  Island  (Marquette),  Lake  Superior. 


the  various  agents  of  erosion,  and  disintegrated.  The  material 
so  eroded  was  used  to  build  up  other  rocks  as  indicated  in  the 
preceding  chapter.  These  newer  rocks,  sandstones,  shales,  etc., 
such  as  are  forming  today  under  similar  conditions,  accumulated 
through  long  ages,  were  upheaved  by  the  crumpling  and  folding 
of  the  crust,  occasionally  into  great  mountain  ranges,  and  thereby 
metamorphosed  into  quartzites,  slates,  and  schists.  The  rock 
layers  were  by  the  same  convulsions  fractured,  and  into  the 


40         A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

great  cracks  and  crevices  fresh  lavas  forced  their  way,  often 
separating  the  strata,  raising  the  upper  ones  as  domes  and  filKng 
the  spaces  so  formed.  So  these  rocks  where  they  are  accessible 
today  are  seamed  with  dykes  (Fig.  25),  as  these  cooled  lava 
intrusives  are  termed,  and  where  their  upper  layers  have  been 
removed  by  erosion  the  old  masses  of  lava  that  filled  the  domes 
stand  up  as  rounded  hills  or  monadnocks  (Fig.  26). 

How  often  this  process  of  rock  destruction,  reformation,  and 
metamorphosis  was  repeated  we  do  not  know.  In  time  simple 
plants  and  animals  appeared.     Through  their  action  beds  of 


Fig.  26. — A  monadnock,  Ishpeming,  Michigan 

carbonaceous  material — •  probably  peat — of  iron  oxide,  and  of 
magnesian  limestones  were  laid  down  with  the  sandstones  and 
shales.  These  also  were  transformed  by  metamorphosis  into 
graphites,  iron  ores,  and  dolomitic  marbles.  The  early  lavas 
granites,  diorites,  and  such  were  in  many  cases  also  greatly 
altered  by  later  strains  and  stresses,  to  which  they  were  sub- 
jected by  crustal  movements.  So  the  earliest  rock  masses  to 
which  we  have  access  consist  of  highly  metamorphic  quartzites, 
slates,  schists,  marbles,  seamed  and  infiltrated  with  granites  and 
with  basic  lavas  that  are  often  so  abundant  as  to  dominate  the 
formation.     These  old  rocks  are  so  folded,  crumpled  (Fig.  27), 


THE  STORY  OF  OUR  ROCK  FOUNDATION 


41 


and  eroded  that  we  may  now  often  examine  their  upturned 
edges  as  they  become  exposed.  The  accessible  rocks  of  these 
early  eras  are  exceedingly  thick,  possibly  one  hundred  thousand 
feet  thick,  thicker  than  all  the  formations  that  came  after  them. 
The  amount  of  erosion  that  they  have  undergone  is  tremendous. 
Rock  layers  miles  in  thickness  have  been  removed  from  these 


Fig.  27. — Folded  and  crumpled  rock  on  the  face  of  a  vertical  cliff  of  jasper 
and  hematite  at  Ishpeming,  Michigan. 

early  land  masses  that  were  of  continental  proportions.  Pre- 
sumably then,  the  Archaeozic  and  Proterozoic  eras  represent 
longer  periods  of  geological  time  than  any  of  the  later  eras,  and 
are  to  be  counted  in  tens  of  millions  of  years,  possibly  hundreds 
of  millions. 

The  early  lands,  made  up  of  these  primitive  rocks  that  served 
as  the  nuclei  for  the  formation  of  the  North  American  continent, 
were  a  group  of  great  islands.  In  general  the  oceanic  depressions 
and  the  continental  elevations  have  existed  from  Archaeozoic 
time,  possibly  from  the  very  first,  much  as  they  now  are.     These 


42  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

islands,  therefore,  arose  from  a  shallow  sea  that  covered  the 
continental  elevations.  In  this  sea  on  the  flanks  of  these  early 
nuclei  were  deposited  the  materials  eroded  from  them  that  made 
up  the  succeeding  formations  of  the  early  Paleozoic,  somewhat 
as  nowadays  in  the  Gulf  of  Mexico  or  the  Mediterranean  are 
accumulating  the  deposits  of  mud  that  in  all  probability  will  in 
time  transform  to  rock  which  may  be  upheaved  to  form  new 
land  masses. 

In  general  it  may  be  said  that  the  rocks  of  the  later  eras — 
Paleozoic,  Mesozoic,  Cenozoic — were  laid  down  in  the  North 
American  region  in  these  shallow  epicontinental  seas,  seas  that 
constantly  changed  their  shape  as  the  surrounding  lands  were 
raised  or  depressed  by  crustal  movements,  or  as  the  ocean 
changed  its  level  when  its  floor  sank  or  rose,  in  which  latter 
process  accumulating  sediments  were  a  major  cause.  Some- 
times the  land  above  the  ocean  was  a  group  of  islands,  sometimes 
it  was  a  continent  with  more  or  less  of  its  central  area  covered 
by  a  sea  and  this  latter  was  connected  by  wide  straits  with  the 
Atlantic,  Pacific,  the  warm  tropical  ocean,  the  cold  Arctic,  one 
at  a  time  or  two  or  more  simultaneously.  The  characters  and 
affinities  of  the  animals  and  plants  whose  remains  are  found  in 
the  successive  rock  formations  give  us  the  best  evidence  regard- 
ing the  oceanic  connections  of  the  seas  in  which  these  formations 
were  deposited. 

The  large  island  made  up  of  the  Proterozoic  rock  complex 
nearest  to  the  Chicago  region  was  extensive,  covering  what  is 
now  northern  Wisconsin,  a  part  of  the  upper  peninsula  of 
Michigan,  much  of  Minnesota,  and  a  large  area  extending  north- 
ward into  Canada.  This  region  now  consists  of  quartzites, 
shales,  schists,  and  dolomites  with  the  intrusive  granites, 
diorites,  and  other  lavas.  If  one  were  to  start,  say,  at  Stevens 
Point  or  at  Grand  Rapids,  which  places  in  Wisconsin  mark  about 
the  southern  limit  of  the  exposed  Proterozoic  rocks  in  our  vicinity, 
and  travel  southeastward  to  central  Illinois,  he  would  pass  over 
he  edges  of  the  succession  of  rock  formations  laid  down  one  on 


THE  STORY  OF  OUR  ROCK  FOUNDATION 


43" 


Tjvi  Ditto, crodcdalongstrcams  (I'l^l 

\a|  1.1  l^wcr  Magncsian    -     -  l-l'l 

^A    Richmond  shale    -         -  | | 

[0|  Niagara  Limestone   -    -  |[  ||| 


Kcwcenasvan,  upper 
Potsdam  Sandstone 
Lower  Magnesian  - 


o 


III 


Fig.  28. — Map  of  the  exposed  geologi- 
cal formations  in  the  Great  Lakes  area. 


St.  Peters  Sandstone  -    -    - 
Galena-Platteville  Limestone 


Ditto,  eroded  along  streams  to  [7=7] 
St.  Peters  Sandstone    -    -    -  \Z\1\ 


Devonian  subdivided  in  l/Vy 
pari — lower,  mid,  upper  f  -  /I 

Mississippian,  sub-  f\vl 

divided  ------  ^  \  1 

Pcnnsylvanian      -     -    -  \-\~\ 
Quaternary      .    -    -    • 


44  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

top  of  another  but  with  many  interruptions  on  the  southern 
flank  of  this  continental  nucleus  (map,  Fig.  28,  compare  Fig.  37). 
The  underlying  formations  would  not  everywhere  be  the  same 
because  in  some  places  the  surface  rock  is  one  of  those  deposited 
early,  and  consequently  has  few  members  of  the  series  below  it, 
and  in  other  places  (those  farther  south) ,  the  rock  is  a  later  forma- 
tion and  has  many  members  below  it.  Often  one  or  more 
members  of  the  series  may  be  absent  at  a  given  locality  if  that 
spot  w^as  land  when  said  member  was  being  deposited  as  might 
readily  be  the  case  since  the  sea  was  so  incessantly  changing  its 
shape  from  period  to  period. 

When  such  a  term  as  the  Niagara  limestone  is  used  it  does  not 
imply  that  the  formation  is  necessarily  homogeneous;  it  may 
consist  of  successive  strata  of  different  sorts  of  rock  or,  if  of  the 
same  sort,  the  succeeding  layers  show  by  the  unlike  animal  and 
plant  fossils  they  contain  that  they  belong  to  different  successive 
fragments  of  geological  time.  The  Niagara  limestone,  the  bed 
rock  of  the  immediate  Chicago  region,  was  laid  down  in  this 
interior  sea  without  any  very  violent  interruptions,  but  the  out- 
let of  the  sea  was  shifted  several  times  during  its  deposition  so 
that  the  fossil  remains  in  successive  levels  of  the  formation  are 
quite  unlike,  some  having  affinities  with  arctic  forms,  some  with 
tropical,  and  some  with  those  of  the  Atlantic  and  Pacific.  The 
formation  is  thus  divisible  into  several  distinct  sets  of  strata. 
In  the  Chicago  region  there  are  at  least  the  lower  coral  beds,  the 
upper  coral  beds,  the  reef  limestones  (Fig.  29),  and  the  Guelph. 
Similarly,  the  Potsdam  sandstone  exposed  farther  north  consists 
of  three  quite  distinct  sets  of  strata,  the  lowest  sandstone  that 
has  a  thickness  of  about  a  thousand  feet,  the  Dresbach  shale  and 
sandstone,  and  the  Franconia  sandstone,  the  two  latter  each 
about  two  hundred  feet  thick.  The  names  applied  to  the  succes- 
sive rock  formations  encountered  in  Illinois  and  adjacent  terri- 
tory are  show^n  in  the  table  at  the  close  of  the  preceding  chapter. 

The  character  of  the  rock,  often  tells  much  of  the  conditions 
prevailing  at  the  time  of  its  formation.     Beds  of  sand  and  gravel 


THE  STORY  OF  OUR  ROCK  FOUNDATION 


45 


are  usually  deposited  in  the  ocean  nowadays  close  inshore,  unless 
the  streams  bringing  in  the  sand  are  swift  or  unless  rapid  ocean 
currents  carry  the  sand  well  out  from  the  shore  line.  Fine  mud 
may  be  carried  in  suspension  long  distances  by  the  water.  It 
settles  only  in  the  quiet  parts  of  the  ocean,  which  are  usually 
the  deepest  ones,  or  in  isolated  bayous  free  from  the  turbulence 
of  the  waves,  from  currents,  and  from  undertow.  Limestone  is 
made  up  of  the  more  or  less  completely  ground  up  shells  of 
animals  like  clams,  oysters,  and  other  similar  forms,  or  the  hard 


Fig.  29. — A  coral  reef  exposed  in  the  quarry  at  Thornton,  Illinois,     Men  are 
standing  at  the  center  of  the  concentric  lines  of  growth.     Photo  by  Link. 

parts  of  corals  or  of  other  animals  whose  skeletons  are  composed 
largely  of  lime.  By  pressure  and  infiltration  this  pulverized 
material  is  later  transformed  to  the  limestone.  Now  animals  like 
corals  and  clams  will  not  live  where  the  water  is  very  muddy. 
Corals  especially  must  have  fairly  deep  and  clear  water  in  which 
to  thrive.  Wherever  an  area  of  limestone  is  found,  especially  if 
it  contains  coral  beds  in  situ,  it  means  that  the  body  of  water 
at  whose  bottom  it  formed  must  have  been  fairly  deep  and 
sufficiently  far  removed  from  the  shore  line  to  be  beyond  the 
deposits  of  sand  or  any  large  amount  of  mud. 


46         A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

With  these  brief  hints  of  the  sort  of  evidence  on  which  the 
geologist  relies  to  reconstruct  the  physiographic  features  of  past 
ages  we  may  sketch  in  bare  outline  the  history  of  the  Chicago 
region  and  adjacent  territory  during  the  time  the  rocks  here- 
abouts wxre  depositing.  During  the  Acadian  period  (Fig.  30)  the 
Potsdam  formation,  largely  sandstone  with  shales,  was  laid 
down  as  sand  and  mud  washed  by  erosive  agencies  from  the 
adjacent  land  and  spread  out  on  the  sea  bottom  and  transformed 
into  rock.  Then  followed  the  Canadian  period  (Fig.  31),  during 
which  limestones,  sandstones,  and  shales  were  formed.  The 
conditions  must,  of  course,  have  frequently  changed  to  permit 
of  such  varied  t}'pes  of  deposits.  First  there  were  laid  down 
thick  beds  of  magnesian  limestone  interrupted  by  layers  of  shale 
and  marl  when  evidently  the  sea  became  shallower  and  muddy 
or  possibly  even  so  shallow  as  to  allow  abundant  vegetation  that 
was  instrumental  in  forming  the  marl.  Later  sandstone  formed 
and  then  more  limestone. 

There  was  next  (Ordovician  period)  a  change  to  a  shallow 
sea  with  swiftly  flowing  currents  and  a  nearby  shore.  The  sea 
contracted  and  its  margins  transformed  to  dry  land.  Possibly 
much  of  the  time  the  sea  completely  disappeared  from  this 
locality,  its  shores  lying  farther  south,  and  the  drifting  sand 
blew  inland  in  great  dunes  covering  wide  areas.  This  sand  in 
time  solidified  to  form  St.  Peter  sandstone.  Again  the  land  sank 
and  the  interior  sea  reformed,  inundating  the  entire  area  about  us 
as  well  as  areas  considerably  to  the  north.  The  sea  bottom  was 
now  deep  enough  along  shore  and  free  enough  from  mud  to  allow 
the  abundant  growth  of  animal  and  plant  life.  Here  where 
Chicago  stands  were  forming  great  beds  of  limestone,  the 
Platteville-Galena  (Trenton)  made  of  the  wave-worn  fragments 
or  even  of  the  perfect  shells  or  skeletons  of  animals  then  living 
along  the  shores,  the  nearest  of  which  were  somewhere  up  in 
what  is  now  mid-Wisconsin.  Animal  life  was  abundant.  There 
were  corals,  brachiopods,  pelecepods,  and  trilobites.  There  were 
also  extensive  beds  of  seaweed   growing   luxuriantly     just   as 


THE  STORY  OF  OUR  ROCK  FOUNDATION 


A1 


Figs.  30-33. — Fig.  30. — Map  showing  land  and  sea  when  the  Potsdam  sand- 
stone was  depositing  (Upper  Acadian).  Fig.  31. — When  Magnesian  limestone 
was  depositing  (Beekmantown).  Fig.  32. — When  Richmond  shales  were  depositing 
(Cincinnatian).  Fig.  2>3- — When  part  of  the  Niagara  limestone  was  depositing 
(Mid-Silurian).  Land  is  white,  sea  finely  lined;  black  shows  areas  of  present 
outcrop.     All  after  Schuchert. 


48         A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

they  do  now  along  the  coral  banks  of  the  Gulf  of  JMexico.  No 
fish  were  swimming  in  the  waters;  they  had  not  yet  appeared 
upon  the  earth.  The  land  areas  would  have  seemed  strange,  too, 
for  the  vegetation  did  not  consist  of  trees  and  grasses  and  flower- 
ing herbs,  but  lowly  plants  like  algae,  liverworts,  and  ferns. 
No  insects  were  flying,  no  vertebrates,  neither  snakes  nor  frogs 
nor  birds,  had  yet  evolved. 

Toward  the  close  of  the  Ordovician  period  another  extensive 
change  in  level  of  the  sea  occurred.  The  central  sea  decreased  in 
size  in  this  region  though  widening  in  the  north  (Fig.  32),  coastal 
plains  emerged  hereabouts,  and  from  them  and  across  them 
great  quantities  of  mud  were  washed  so  the  shallow  sea  became 
unfit  for  many  animals.  Many  kinds  were  forced  to  migrate  to 
deeper  seas,  many  perished,  and  their  remains  are  very  abundant 
in  the  beds  of  shales  and  sandy  limestones  known  as  Richmond 
shales.  This  stratum  formed  in  the  Chicago  region  to  a  depth  of 
100  feet  and  elsewhere  in  the  interior  sea  became  even  thicker. 

The  formation  of  the  Richmond  shales  and  sandstone  was  ter- 
minated by  a  rise  of  the  land  so  that  the  northern  portion  of  the 
interior  sea  including  the  Chicago  region  became  dry  land,  subject 
then  to  the  destructive  forces  of  erosion.  So  closed  the  Ordovician 
period,  and  the  Silurian  period  w^as  ushered  in.  As  it  advanced 
the  sea  deepened  rapidly  (Fig.  ;^;2,)  until  conditions  were  favor- 
able again  for  an  abundant  animal  life  along  the  shore  and  for 
corals  in  the  deeper  waters.  Many,  many  generations  of  animal 
forms  wdth  calcareous  skeletons  lived  and  died  and  left  their  shells 
or  other  hard  parts  to  form  the  thick  deposits  that  later  trans- 
formed into  Niagara  limestone  to  a  depth  of  from  250-400  feet 
in  the  Chicago  region. 

This  rock  is  full  of  fossils  that  help  us  gain  a  clear  idea  of  the 
animals  that  lived  upon  the  sea  bottom  where  today  Chicago 
stands  and  that  contributed  their  skeletons  and  shells  to  help 
form  the  rock  out  of  which  Chicago's  inhabitants  constructed 
their  buildings  in  the  days  before  cement  so  largely  replaced 
building  stone  (Fig.  34). 


TEE  STORY  OF  OUR  ROCK  FOUNDATION 


49 


J.J' 


\ 


/; 


/ 


P 


/~ 


/ 


■^ 


,%■ 


■/ 


^ 


Fig.  34. — Animal  fossils  from  Niagara  limestone  in  the  Chicago  region, 
a,  a  coral,  Favosites  niagarensis  Hall;  h,  Phraginoceras  neslor  Hall;  c,  Pentamcrus 
oblongus  Sowerby;  d,  a  trilobite,  Calymene-  celebra  Raymond;  e,  Amphicoelia 
neglecta  McChesney;  /  and  g,  crinoids:  /,  Eucalyptocrimis  as  per  Weller; 
g,  Caryocrinites  ornatus  Say;  h,  Strophostylus  Icvatus  Hall;  /,  a  straight-shelled 
cephalopod,  Dawsonocerus  anmdatum  Sowerby.     Photo  by  Fenton. 


50         A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

There  were  great  reefs  of  corals  off  the  shore  of  the  nearby 
land,  and  other  species  of  corals  that  lived  solitary  lives  rather 
than  in  colonies  were  abundant.  There  were  sponges,  grap- 
tohtes,  polyps,  crinoids  like  stemmed  starfish,  ordinary  star- 
fish, lamp  shells  or  brachiopods,  clams,  snails,  cephelopods, 
somewhat  related  to  the  pearly  nautilus  of  today,  only  having 
long,  straight  shells  instead  of  coiled  ones;  there  were  primitive 
crustaceans  like  the  trilobites.  Undoubtedly  on  the  land  about 
the  sea  grew  giant  club  mosses,  tree  ferns,  cycads,  and  the  lower 
t}pes  of  flowering  plants  such  as  the  conifers  and  the  grasses. 
Centipedes  and  lowly  types  of  insects  were  also  probably  seen. 

A  period  of  upheaval  followed  the  deposit  of  the  Niagara 
limestones  closing  the  Silurian  period,  and  the  ■  Chicago  region 
was  once  more  dry  land  undergoing  erosion.  How  long  this 
condition  persisted  it  is  hard  to  say,  but  there  followed  another 
period  of  depression  when  the  sea  again  occupied  this  site.  The 
inland  sea  was  becoming  more  restricted,  however,  deposition 
was  going  on  in  limited  basins,  and  the  wash  from  the  land  was 
increasing  as  the  land  area  grew.  In  this  Devonian  period  the 
strata  formed  consisted  of  shales  and  limestones.  Only  remnants 
of  them  exist  in  a  few  locations  about  Chicago,  however,  for  the 
sea  disappeared  in  our  region  rather  promptly  and  all  the  Devo- 
nian rocks  that  had  formed  were  eroded  away  leaving  the  Niagara 
limestone  bare  except  where  an  occasional  fissure  in  it  had 
happened  to  receive  and  retain  some  of  the  Devonian  deposits. 
Such  have  been  found  at  the  quarry  at  Elmhurst  and  at  Lyons. 
These  deposits,  though  scanty,  are  exceedingly  interesting,  for 
they  contain  many  sharks'  teeth,  local  evidence  of  the  presence 
of  the  fishes  in  the  Devonian  seas;  they  were  so  abundant,  so 
dominant,  that  the  Devonian  is  known  as  the  age  of  fishes. 

So  far  as  we  know,  the  ocean  never  again  overflowed  the  site 
of  Chicago.  This  immediate  region  remained  exposed,  subject 
to  the  action  of  the  elements,  undergoing  extensive  erosion 
during  the  rest  of  the  Paleozoic  and  during  all  of  the  Mesozoic 
and  the  Cenozoic.     Our  local  rocks  afford  no  evidence  of  the 


THE  STORY  OF  OUR  ROCK  FOUNDATION 


51 


changes  that  occurred  through  all  these  eventful  ages,  except  the 
tokens  of  the  glacial  period  that  came  in  late  Cenozoic  time,  as 
will  be  described  shortly. 

The  whole  central  region  of  Illinois  is  occupied  by  rocks  of 
the  later  Paleozoic  era  (map,  Fig.  28)  commonly  known  as  the 
coalbeds.  The  seas  (Fig. 3 5) 
in  which  these  rocks  were 
deposited  were  at  times  suf- 
ficiently deep  to  allow  mud 
deposits  to  accumulate  that 
later  were  transformed  to 
shales  and  slates;  then  again 
they  became  so  shallow  they 
were  covered  with  swamp 
vegetation.  Here  grew 
dense  jungles  of  cycads  and 
calami tes,  rushes  and  sedges, 
gigantic  ferns  and  probably 
conifers,  a  rank  growth 
whose  trunks  and  stems 
and  leaves  falHng  into  the 
shallow  water  accumulated 

until  a  thick    bed   of   vege-  ^^^'  35— North  America  in  the  Upper 

Pennsylvanian  when  the  IlHnois  coal  beds 

table   matter  lay  upon    the     were  being  deposited.    Land  white,  seas  lined. 

floor  of  the  sea.      This  was     ^^^^'^  areas  indicate  land  where  these  strata 

.  ,  1    1      •  1         are  now  surface  formations.    After  Schuchert. 

covered  by  mud  durmg  the 

next  period  of  depression  and  gradually  by  pressure  and  heat 

was  converted  into  coal. 

The  old  dump  piles  of  refuse  slate,  shale,  and  poor  coal  afford 
excellent  opportunities  to  secure  fossils  of  this  period.  Fern 
leaves,  bark  of  the  tree-fern  trunks,  calamite  stems,  fossils  of 
various  animal  types,  including  an  occasional  fish  skeleton,  and 
that  of  the  early  amphibians  are  to  be  had  by  patient  search 
(Fig.  36).  You  can  easily  imagine  the  picture  of  the  region 
when  the  coal  was  forming:   the  dark  swamp  forest,  the  moist, 


52  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

warm  air  heavy  with  abundant  carbon  dioxide,  tree  ferns, 
cycads,  grasses,  rushes — an  aknost  impenetrable  jungle — a  loose, 
swampy  soil,  a  vegetable  slush  into  which  the  fallen  trunks  sink, 
insects  somewhat  like  roaches  crawl  over  the  vegetation — some 
like  immense  dragon  flies  are  darting  about  in  the  air. 

In  the  adjacent  sea  are  sponges,  corals,  graptoHtes,  sea 
urchins,  starfish,  crinoids,  brachiopods,  clams,  snails,  trilobites, 
shrimps  (Fig.  36^),  cephalopods,  fish  of  the  lower  types,  amphibi- 
ans, and  boring  in  the  mud  banks  are  sea  worms  of  various  sorts. 

Centuries  passed  by  in  the  Chicago  region,  hundreds  of  them. 
In  the  distant  seas  were  forming  the  thousands  of  feet  of  rock 
strata  that  make  up  the  remainder  of  the  Paleozoic,  the  Mesozoic, 
and  the  Cenozoic  rocks.  Undoubtedly  the  rocks  of  the  Chicago 
area,  disintegrated  slowly  under  all  the  processes  of  weathering, 
formed  deep  soil,  and  upon  this  there  grew  a  rank  vegetation. 
Here,  in  time,  occasionally  perhaps  roamed  those  huge  reptiles 
whose  fossils  are  to  be  seen  in  the  collection  of  the  Field  Museum 
and  still  later  various  t}^es  of  mammals  that  were  precursors  of 
present-day  forms.  The  map  (Fig.  28)  gives  the  positions  and 
relations  of  the  main  formations  occurring  as  surface  rocks  over 
a  wide  area  about  Chicago. 

A  great  fold  of  the  strata  occurs  in  Illinois,  a  broad  up-arching, 
its  axis  running  southeast-northwest  and  continuing  into  Wis- 
consin on  the  one  hand  and  into  Indiana  on  the  other.  The  rock 
originally  lying  on  the  top  of  this  arch  has  been  removed  by 
erosion  as  a  result  of  which,  it  will  be  obserAxd,  there  is  in  the 
northern  part  of  the  state  a  broad  central  band  of  Galena- 
Platteville  limestone  bordered  on  the  east  and  west  by  the  Rich- 
mond (^laquoketa)  shale,  while  farther  out  still  lie  bands  of  the 
Niagara  limestone  on  the  eastern  one  of  which  Chicago  is  situated 
(see  Fig.  37). 

The  nearest  point  to  Chicago  at  which  the  Richmond  shale 
is  found  is  in  the  neighborhood  of  Joliet,  at  the  mouth  of  Rock 
Run,  near  the  old  canal  some  four  miles  southwest  of  the  city 
and  in  the  same  neighborhood  in  an  abandoned  quarry  near 


THE  STORY  OF  OUR  ROCK  FOUNDATION 


53 


Fig.  36. — Fossils  from  the  Pennsylvanian  coal  measures,  Mazon  Creek,  111. 
All  plants  except  e.  a,  Alethopteris  amhigua  Lesqx.;  b,  Neuropteris  vermiciilaris 
Lesqx.;  c,  a  horsetail,  Annularia  stellata  Schl.;  d,  Sphenophyllum  marginatum 
Brougn.;  e,  a  crustacean,  Acanthotelson  stimpsoni  M.  &  W.;  /,  Palmalopteris  furcala 
Potonid.;  g,  bark  of  Sigillaria  sillimani  Brougn.     Plant  photos  by  P.  O.  Sedgwick. 


51 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


I  e  lower  end  of  Flathead  mound  where,  however,  it  is  nearly 
covered  by  the  crumbling  Niagara  limestone  above  it. 

The  map  will  show  the  nearest  point  at  which  the  Galena- 
Platteville  is  exposed.  In  several  counties  along  the  crest  of 
the  arch  the  streams  have  cut  down  sufficiently  to  expose  the 
St.  Peter's  sandstone  that  underlies  the  Galena-Platteville  and 
in  a  very  few  spots  to  expose  the  deeper  Lower  Magnesian  Hme- 
stone  (Prairie  du  Chien) .  Such  cutting  to  the  St.  Peter's  occurs 
in  eastern  Carroll  County,  in  Ogle  County  south  of  Oregon  on 
the  Rock  River,  and  along  many  streams  in  southwestern 
Wisconsin.     The  cutting  runs  deeper,  even  to  the  Lower  Mag- 


FiG.  37. — Diagrammatic  section  across  the  arch  of  rocks  in  Illinois.  The 
lower  section  cuts  through  Joliet  (J),  Marseilles  (M),  Ottawa  (O),  and  Prince- 
ton (P).  The  upper  one  is  farther  north,  (i)  Lower  Magnesian  formation; 
(2)  St.  Peter's  sandstone;  (3)  Galena-Platteville  formation;  (4)  Richmond  shale; 
(5)  Niagara  limestone;   (6)  Devonian;   (7)  Pennsylvanian. 

nesian'on  the  Ilhnois  River  in  the  neighborhood  of  La  Salle 
and  Utica.  Between  these  it  is  exposed  along  the  railroad 
tracks.  It  is  also  seen  near  the  mouths  of  several  creeks  flow- 
ing into  the  Vermilion  River. 

The  Ilhnois  is  here  flowing  through  country  of  w^hich  the  sur- 
face rock  belongs  to  the  Pennsylvanian  coal  measures,  so  the  river 
has  cut  through  these,  through  the  Galena-Platteville  limestone 
and  St.  Peter's  sandstone,  to  the  Lower  Magnesian  limestone. 
The  rocks  of  the  Pennsylvanian  formation  are  most  easily  reached 
from  Chicago  at  Braiderwood  or  Coal  City,  on  the  Chicago  & 
Alton  Railroad  and  Atchison,  Topeka  &  Santa  Fe  Railway, 
respectively,  where  they  may  be  examined  in  the  rock  dumps 


THE  STORY  OF  OUR  ROCK  FOUNDATION  55 

of  the  coal  mines.  The  rocks  of  the  Devonian  and  Mississippian 
are  older  than  the  Pennsylvanian  but  are  not  exposed  in  the  state 
nearer  than  its  western  side  near  Rock  Island.  They  are  found 
nearer  Chicago,  in  Wisconsin  just  north  of  Milwaukee,  and  also 
in  southwestern  Michigan.  Remnants  of  the  Devonian  rocks 
are  preserved  occasionally  in  the  cracks  and  crevices  of  the 
Niagara  limestone  in  this  immediate  vicinity. 


CHAPTER  IV 


THE  GLACIAL  PERIOD 

REAT  glaciers  came  out  of  the  north  in 
recent  geological  time  covering  all  the 
northern  part  of  North  America  (Fig. 
^S),  Europe,  and  Asia,  glaciers  compara- 
ble to  the  great  ice  cap  that  now  covers 
all  the  antarctic  lands  or  to  the  one 
that  still  over-rides  Greenland.  The 
glacial  period  probably  came  on  gradu- 
ally. The  snow  accumulated  in  the  north  more  rapidly  during 
the  long  winters  than  the  summer's  duninishing  heat  could 
melt  it.  It  grew  deeper  and  deeper.  The  chill  of  the  great 
snowfields  was  felt  in  the  lands  south  of  them  where  the  climate 
became  more  rigorous  and  the  snows  began  to  pile  up;  thus  the 
snowfields  became  more  extensive.  In  the  far  north  the  snow 
banked  up  miles  deep  until  the  lower  layers  under  the  terrific 
pressure  were  transformed  into  ice  and  were  squeezed  out, 
moving  southward  over  once  fertile  lands  and  transforming 
them  into  arctic  desolation.  This  same  process  is  going  on  now 
on  a  small  scale  in  the  high  mountains  all  over  the  world  where 
lakes  of  snow  in  the  upper  valleys  outlet  by  rivers  of  ice  that 
slowly  push  their  way  down  the  slopes  (Fig.  lo). 

What  agencies  brought  on  the  glacial  period  has  been  a 
matter  of  interesting  conjecture.  The  uplift  of  the  northern 
part  of  the  continent  to  Alpine  height,  a  shift  of  the  warm  ocean 
currents  so  they  did  not  flow  into  the  northern  oceans,  a  change 
in  the  position  of  the  earth's  axis  so  that  winter  came  in  the 
northern  hemisphere  when  the  earth  in  its  orbit  was  farthest  from 
the  sun  instead  of  nearest  as  now,  a  change  of  eccentricity  of  the 
earth's  orbit,  an  increase  in  the  amount  of  carbon  dioxide  in  the 

56 


THE  GLACIAL  PERIOD 


57 


T^ 


atmosphere  which  would  shut  out  much  of  the  sun's  heat — all 
these  have  been  suggested  as  possible  causes,  and  each  has  been 
judged  more  or  less  incompetent  to  produce  the  results.  Possi- 
bly several  causes  co-operated  to  produce  the  glacial  age.  It  is 
estimated  by  Penck  that  a  reduction  in  the  average  annual 
temperature  of  less  than  15° 
F.  would  bring  on  a  return 
of  the  glacial  period  in  North 
America,  a  slight  change 
apparently  to  produce  such 
far-reaching  consequences. 

If  the  exact  causes  still 
are  matters  of  debate,  the 
fact  is  certain  that  the  Chi- 
cago area  was  covered  with 
a  deep  glacier  and  that  not 
once  but  several  times,  for 
there  is  good  evidence  that 
a  succession  of  glacial 
periods  have  followed  each 
other  in  North  America. 
These  have  been  designated 
the  Aftonian  or  Jerseyan,  the 
Kansan,  the  lUinoian,  the 
lowan,  and  the  Wisconsin. 
The  oncoming  of  the  Wis- 
consin ice  sheet  occurred 
possibly  twice  as  long  ago  as  has  elapsed  since  the  last  ice  dis- 
appeared completely  here,  a  matter  of  some  ten  thousand  years. 
The  lowan  began,  roughly,  four  times  as  long  ago;  and  the 
Illinoian,  eight  times  or  more.  The  time  in  which  we  live  may 
be  one  of  the  interglacial  periods,  and  it  may  be  that  many  of 
the  mighty  works  of  our  much  vaunted  civilization  will,  in  the 
distant  future,  be  blotted  out  by  the  renewed  ruthless  advance 
of  the  great  ice  cap. 


Fig.  38. — Map  of  North  America  at 
the  time  of  the  glacial  period.  Note  that 
the  southern  limit  of  the  glacier  was  a 
little  short  of  the  southern  boundary  of 
what  is  now  Illinois  and  Indiana  and  that 
there  was  an  unglaciated  area  in  Wiscon- 
sin and  north w^estern  Illinois.    (See  Fig.  51.) 


58 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


WTiile,  as  suggested  in  the  last  chapter,  there  is  no  evidence 
that  rock  strata  were  laid  down  in  the  Chicago  region  after  the 
Devonian  period  of  geological  time,  in  the  long  stretch  of  ages 
that  elapsed  between  then  and  the  onset  of  the  last  glacial  period 
many  changes  were  going  on  in  the  area.  For  many  centuries 
the  forces  of  erosion  were  active.     The  Devonian  rocks  and 


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Fig.  39. — An  attempted  reconstruction  of  the  preglacial  drainage  of  the 
Great  Lakes  region.     Present  lakes,  streams,  and  boundaries  in  dotted  lines. 

possibly  later  ones  on  top  of  them  were  w^orn  away  until  only 
vestiges  of  them  wxre  left  and  the  removed  material  was  carried 
off  into  the  oceans.  The  surface  of  the  hard  Niagara  limestone 
and  of  the  softer  Richmond  shale  was  dissected  by  the  rivers 
into  steep-sided  valleys  that  later  broadened  and  became  less 
abrupt  w^hile  rounded  hills  of  goodly  height  stood  between.  The 
rocks  gradually  disintegrating  through  hundreds  of  thousands 
of  years  formed  deep  soil.  Vegetation  flourished  and  animal 
life  found  abundant  shelter  and  food.  Probably  where  Lake 
Michigan  now  stands  was  a  broad  and  fertile  valley. 


THE  GLACIAL  PERIOD  59 

It  is  now  impossible  to  be  certain  of  the  topography  of  the 
country  hereabout  before  the  glacier  came  to  make  its  changes, 
for  that  old  suriace  was  undoubtedly  greatly  altered,  its  rock 
foundation  pretty  completely  covered  by  the  debris  the  glacier 
left.  Still,  knowing  the  general  lay  of  the  old  rock  strata  and 
their  nature,  and  learning  something  from  the  rock  hilltops  that 
crop  out  of  the  glacial  deposits  and  from  well  borings  that  pene- 
trate to  the  rock  surface,  it  is  judged  that  the  old  valley  now 
occupied  by  Lake  Michigan  extended  past  the  site  of  Chicago, 
through  rugged  hill  country,  and  that  in  it  flowed  a  river,  part 
of  the  preglacial  river  system,  a  more  or  less  conjectural  diagram 
of  which  is  shown  in  the  accompanying  figure  (Fig.  39).  Fortu- 
nately there  is  one  region  not  far  removed  from  Chicago  which 
presents  no  evidence  of  the  recent  glacier,  and  it  is  believed  it 
escaped  the  late  ice  covering — ^an  island  in  the  broad  ice  flow. 
This  is  the  unglaciated  region  of  northwestern  Illinois  and  south- 
western Wisconsin.  It  is  a  well-drained  region  with  much 
branched  rivers  flowing  in  deeply  cut  valleys  between  the 
rounded  hills.  It  is  not  a  region  of  lakes  or  ponds.  The  soil 
grades  insensibly  into  the  rock — fine  soil  on  top,  coarser  below, 
finely  broken  rock,  coarser  fragments,  then  the  rock  ledge  just 
beginning  to  disintegrate.  It  is  probably  quite  typical  of  the 
Chicago  region  in  preglacial  times  except  that  the  processes  of 
erosion  had  not  gone  so  far  here  before  they  were  interrupted 
by  the  onset  of  the  glacier. 

As  the  great  glacier  came  pushing  its  way  southward  it 
shoved  ahead  of  it  some  of  the  soil  scraped  from  the  land,  soil 
that  had  been  accumulating  through  many  centuries  of  rock 
decay;  or  else  the  frozen  soil,  together  with  the  rock  fragments 
below  it,  was  over-ridden  by  the  glacier,  frozen  to  its  base,  and 
so  became  a  part  of  the  onward-moving  mass  and  ultimately  was 
incorporated  in  the  plastic  ice.  Then  this  same  material  became 
in  the  grip  of  the  glacier,  an  efficient  grinding  and  polishing  tool, 
This  is  found  to  be  true  of  present-day  glaciers.  They  are 
mighty  agents  of  erosion.     While  the  ice  itself  glides  over  the 


6o 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


bed  rock  with  little  wear  or  tear,  rock  fragments  held  by  the  ice 
make  deep  grooves,  imbedded  sand  grains  striate  the  rock  sur- 
face in  the  direction  of  glacial  motion,  while  finer  particles  like 
clay  polish  it.  Such  work  necessarily  wears  away  the  graving 
tools.  Rock  fragments  held  by  the  ice  and  pressed  against  the 
rock  over  which  it  moves  are  themselves  planed  off,  polished, 
and  scratched,  first  on  this  side,  then  on  that,  as  they  turn  in 


Fig,  40. — A  good-sized  glacial  bowlder  on  Lake  JNIichigan  shore  near  Glencoe 

the  somewhat  plastic  ice.  Ultimately  they  are  ground  to  powder 
unless  they  are  dropped  in  the  morainal  material,  in  which  case 
they  are  subangular  stones  more  or  less  marked  by  their  use 
(Fig.  40) .  The  bed  rock  where  freshly  uncovered  in  the  Chicago 
region  often  shows  a  polished  surface,  sometimes  striated,  occa- 
sionally deeply  grooved,  mute  evidence  of  events  that  were 
transpiring  here  during  the  great  ice  age.  In  general  these 
markings  are  parallel  and  have  a  northeast-southwest  direction, 


THE  GLACIAL  PERIOD  6l 

showing  the  compass  point  from  which  the  glacier  came  here. 
At  times  the  scratches  cross  each  other,  indicating  at  least  local 
changes  in  the  direction  of  movement  of  the  ice  (Fig.  41). 

At  last  in  its  onward  flow  the  glacier  pushed  its  way  south- 
ward into  a  region  so  warm  that  the  front  of  the  glacier  melted 
away  as  rapidly  as  new  ice  arrived.  The  bulk  of  the  coarse 
rock  fragments  it  was  carrying,  together  with  much  of  the  finer 


'0 


Fig.  41. — Grooves  and  scratches  on  bed  rock  due  to  glacial  erosion,  Stony- 
Island,  Chicaffo. 


'-&'■ 


stuff,  was  deposited  along  this  line  where  the  glacier  front  stood 
perhaps  for  hundreds  of  years,  piling  up  in  great  unsorted  heaps 
as  the  moving  ice  continually  brought  fresh  supplies.  Thus  it 
formed  out  of  this  debris  pillaged  from  a  continent  the  terminal 
moraine.  The  Illinois  glacier  is  the  first  one  to  leave  undisputed 
evidence  of  itself  in  our  state ;  it  pushed  south  approximately  to 
the  present  location  of  the  Ohio  River  and  deposited  its  terminal 
moraine.     This  glacier,  therefore,  extended  past  our  present  loca- 


62 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


tion  at  Chicago  some  three  hundred  miles.  Nansen  found  in  cross- 
ing Greenland  that  the  ice  surface  rose  for  the  first  75  miles 
from  the  west  coast  nearly  90  feet  per  mile,  then  at  a  decreasing 


Fig.  42. — The  moraines  of  the  glacier  about  south  end  of  Lake  ]\Iichigan; 
old  Lake  Chicago  in  heavy  horizontal  shading,  Lake  Morris  in  broken  hori- 
zontal lines. 

rate  averaging  26  feet  per  mile.  On  this  basis  of  calculation  the 
ice  of  the  Illinoian  sheet  at  Chicago  must  have  been  about 
twelve  thousand  feet  deep.  Even  if,  to  be  on  the  safe  side,  this 
estimate  were  cut  in  half,  it  would  still  make  the  mass  more  than 
a  mile  in  thickness,  a  ponderous  thing,  capable  of  over-riding 


THE  GLACIAL  PERIOD  63 

hills  and  planing  down  their  tops,  of  gouging  out  valleys,  and  of 
transporting  incalculable  loads  of  debris. 

Gradually  the  rigorous  climate  of  this  early  period  was 
mollified.  Spring  came  earlier  as  the  years  passed  and  the 
autumn  days  grew  warmer,  so  that  the  glacier  beat  a  slow  retreat. 
As  the  front  slowly  melted  back  through  many,  many  years  the 
rock  and  soil  debris  held  in  the  ice  was  deposited  all  over  the 
smoothed  and  scored  rock  surface  in  an  unsorted  condition, 
the  finer  material  containing  subangular  rocks  and  bowlders  of 
all  sizes,  polished  and  scratched.  It  is  the  same  sort  of  drift 
that  makes  up  the  terminal  moraine  but  now  constitutes  the 
ground  moraine,  the  deposit  laid  down  by  the  retreating  glacier. 
This  withdrawal  of  the  ice  was  irregular;  it  would  fall  back 
only  to  advance  again  as  a  few  cold  winters  reinforced  its  reserves. 
Its  front  was  constantly  shifting  as  melting  or  temporary  advance 
went  on  at  some  points  more  rapidly  than  at  others,  due  to  local 
conditions.  The  deposited  drift  was  therefore  left  in  erratically 
arranged  heaps  with  irregular  hollows  between.  The  drift  some- 
times buried  great  blocks  of  ice  which  later  melted,  leaving  de- 
pressions. Most  of  the  valleys  were  without  outlets  except  as 
chance  arranged  them,  so  that  later  they  were  occupied  by 
lakes,  ponds,  bogs,  marshes,  and  swamps. 

This  Illinoian  ice  age  was  followed  by  a  long  interval  when 
the  surface  of  the  soil  was  subject  to  erosion;  when  in  all  prob- 
ability forests  developed  and  grassy  plains  and  valleys  lay 
luxuriant  in  the  warm  sunshine.  Other  ice  sheets  again  invaded 
the  region,  however,  bringing  desolation.  In  these  later  ages, 
the  lowan  and  the  Wisconsin,  the  ice  in  the  Chicago  region  was 
nowhere  nearly  as  thick  as  in  the  case  of  the  Illinoian.  These 
later  ice  sheets  apparently  over-rode  the  early  drift  deposits, 
piling  up  their  moraines  and  other  deposits  upon  the  earlier  ones. 
The  average  depth  of  the  drift  in  the  Chicago  region  is  probably 
1 30-1 4c  feet,  as  determined  by  wells,  with  a  maximum  thickness 
of  somewhat  over  twice  this  figure.  Most  of  this  is  the  deposit 
of   the  Wisconsin  period.     In  some  places  in  our  immediate 


64  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

region  it  is  underlaid  by  a  deposit  that  has  been  regarded  as 
belonging  to  one  of  the  earlier  ages,  probably  the  Illinoian.  A 
coarse  conglomerate  made  up  of  glaciated  pebbles,  5-10  per  cent 
of  which  are  of  granite  or  diabase,  is  seen  underlying  the  Wis- 
consin drift  north  of  Lockport  just  beside  the  Chicago  and 
Joliet  trolley  line  and  at  several  points  within  the  city  limits  of 
Joliet,  one  opposite  the  brick  switch  house  about  a  mile  north  of 
the  Rock  Island  Depot.  This  deposit  is  well  cemented  together 
with  carbonate  of  lime,  transforming  the  original  bed  of  gravel 
into  rock.  Its  surface  is  said  to  give  some  indication  of  having 
been  abraded  by  the  later  ice  sheet.  It  seems  more  probable 
that  these  deposits  are  part  of  the  valley  train  described 
below. 

The  surface  features  of  the  Chicago  area  are  chiefly  due  to  the 
deposits  of  the  last  of  the  great  glacial  periods — the  Wisconsin — 
and  to  postglacial  changes  in  these.  The  front  of  this  ice  sheet 
retreated  by  several  steps,  standing  still  long  enough  several 
times  to  make  a  succession  of  terminal  moraines  as  seen  on  the 
accompanying  maps  (Figs.  42,  43). 

Each  of  the  moraines  marks  a  stage  in  the  recession  of  the  ice  border, 
when  the  rate  of  melting  was  temporarily  checked  and  the  edge  of  the  ice 
became  nearly  stationary.  At  such  times  the  drift,  which  was  being  moved 
forward  to  the  melting  border  and  deposited  there,  accumulated  to  great 
thickness.  When  the  ice  border  receded  a  relatively  smooth  lowland  was 
laid  bare  behind  the  belt  of  thick  drift.  This  extended  to  the  point  where 
another  halt  of  the  ice  caused  the  making  of  another  ridge  of  drift. 

Of  these  moraines  the  last  formed- — -the  one  nearest  Chicago, 
the  Valparaiso  moraine — is  the  highest  and  broadest.  It  marks, 
evidently,  a  prolonged  stand  of  the  glacier's  front.  Its  sur- 
face varies  from  an  almost  smooth  or  gently  undulating  plain 
(Minooka  Ridge)  to  typical  rounded  hills  and  saucer-shaped 
valleys  with  contained  ponds  or  swamps.  The  last  type  is  well 
seen  on  .Mount  Forest  Island,  as  one  walks  south  from  Willow 
Springs,  or  in  the  hill  territory  about  Palos  Park.  The  hills  and 
valleys  are  not  so  abrupt  or  so  high  as  they  are  in  the  kettle- 


THE  GLACIAL  PERIOD 


65 


Fig.  43.— Map  of  Illinois  moraines.     Bulletin  State  Geological  Survey 


66 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


moraine  territory  of  southern  Wisconsin  about  Gary,  for  instance; 
still  it  is  very  evidently  moraine  topography  (Fig.  44). 

The  melting  front  of  the  glacier  was  pouring  out  torrents  of 
water  that  discharged  in  a  mighty  river  down  a  valley  occupied 
now  by  the  Desplaines,  then  the  old  preglacial  valley  and  much 
deeper  than  the  present  one.  The  river  discharged  for  a  time, 
at  least,  into  a  lake  that  occupied  the  Morris  Basin  (see  map), 
and  this  in  turn  had  its  outlet  along  the  present  Illinois  Valley 
then  also  much  deeper.  This  great  river  laid  down  material 
along  its  course,  for  it  came  away  from  the  glacier  so  charged 


Fig.  44. — Typical   moraine    country,    kettle-shaped    hills    and    valleys,    the 
latter  often  with  ponds  o    lakes  with  no  outlet. 

with  sediment  that  wherever  its  current  was  checked  in  the  least 
it  deposited  the  gravel  and  sand.  So  it  filled  up  its  valley,  and 
tributary  streams  filled  up  theirs  with  long-drawn-out  deposits 
known  as  valley  trains.  It  spread  out  a  great  fan-shaped  delta 
at  its  entrance  into  the  lake  of  the  Morris  Basin.  The  old  valley 
was  filled  to  a  level  some  fifty  feet  above  the  present  stream  as  is 
evident  from  the  remnants  of  the  old  valley  train  still  recogniz- 
able. *' Opposite  Lockport  where  the  road  to  Plainfield  leaves 
the  valley  floor"  is  a  flat- topped  gravelly  ridge,  a  part  of  the 
old  valley  fill.  Some  four  miles  below  Joliet  there  are  flat-topped 
areas  of  gravel  standing  up  conspicuously  in  the  present  valley. 


THE  GLACIAL  PERIOD 


67 


generous  remnants  of  the  old  valley  train.  The  formation  is 
known  as  ^'Flathead"  (Fig.  45).  At  a  level  corresponding  to  its 
top  on  the  north  side  of  the  valley  may  be  seen  a  conspicuous 
shelf  of  similar  gravel  along  which  the  upper  road  runs  for  some 
distance.  These  gravel  deposits  are  rapidly  being  removed  for 
commercial  purposes. 

Small  streams  rushing  from  points  at  the  front  of  the  glacier, 
charged  with  sediment,  often  deposited  such  material  close  to  the 


Fig.  45. — Flathead  near  Joliet.    Detail  at  right,  to  show  size  of  the  gravel 

glacier's  edge  as  the  current  was  checked  when  the  stream  spread 
out  on  to  the  open  plain.  Such  mounds  of  debris,  always  irregu- 
larly stratified,  are  known  as  kames.  Good  examples  of  such  are  to 
be  seen  one  and  one-half  miles  northeast  of  Naperville,  where  the 
road  to  Wheaton  passes  between  two  dome-shaped  hillocks,  both 
kames.  There  is  a  large  one  east  of  Glen  Ellyn,  cut  by  the 
Aurora,  Elgin  and  Chicago  Electric  Railroad.  The  east  branch 
of  the  DuPage  River  is  turned  out  of  its  southerly  course  by  it. 
In  the  southern  portion  of  the  glacier  the  warm  sun  melted 
the  ice  on  its  top  as  ice  and  snow  melt  in  the  early  days  of  spring. 


6S 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


and  the  water,  finding  its  way  through  cracks  and  crevices,  flowed 
along  in  a  stream  underneath  the  glacier.  Such  streams  often 
carried  and  then  deposited  material  in  elongated  heaps  of  more 
or  less  stratified  gravel  and  sand.  Now  that  the  ice  is  gone,  these 
show  as  elongated  hills  known  as  eskers. 

This  glacial  drift  is  made  up  of  soil  through  which  are  scat- 
tered bowlders,  small  and  large,  or  if  the  material  is  sorted  by 
water,  it  is  laid  down  in  layers,  coarse  or  fine  according  to  the 
speed  of  the  current  that  carried  it  to  the  present  location.     The 


Fig.  46. — Crystals;    at  left  cubes  of  galenite,  at  right  quartz  with  a  single 
quartz  crystal  in  center  foreground,  in  rear  of  it  tourmaline  crystal  in  matrix. 

bowlders  and  stones  are  subangular  and  more  or  less  scratched  and 
grooved.  A  large  percentage  of  them  are  hmestone,  since  the 
bed  rock  for  a  couple  of  hundred  miles  to  the  north  is  also  lime- 
stone. But  there  are  many  samples  of  sandstone,  quartzite, 
granite,  gneiss,  schist,  diorite,  diabase,  and  greenstone  that  have 
been  brought  into  our  region  by  the  glacier  from  the  ledges  in 
northern  Michigan  and  Canada  where  are  located  the  nearest 
outcrops  of  these  rocks  in  the  direction  from  which  the  glacier 
came. 

A  rock  is  either  a  mass  of  some  one  mineral  or  made  up  of 
grains  of  several  minerals.     A  mineral  is  a  homogeneous  inorganic 


THE  GLACIAL  PERIOD 


69 


substance  of  definite  or  nearly  definite  chemical  composition,  and 
it  crystallizes  into  regular  and  constant  form.  Thus  quartz,  one 
of  the  most  common  of  all  minerals,  is  an  oxide  of  sihcon,  SiOz, 
with  some  water  added  if  in  crystalline  form.  The  crystals  are 
six-sided  prisms  with  six-sided  pyramids  at  each  end,  if  perfect 
(Fig.  46).     This  mineral  may  occur  in  great  masses  or  it  may 


Fig.  47. — Piece  of  orthoclase  feldspar  showing  cleavage 

be  merely  one  constituent  of  complex  rocks.     It  is,  for  instance, 
an  essential  element  in  granite. 

Not  many  minerals  occur  as  conspicuous  ingredients  in  the 
rocks  of  the  Chicago  region.  It  would  be  well  to  study  these 
few  in  the  collections  to  be  found  in  the  local  museums  like  that 
of  the  Chicago  Academy  of  Science  or  the  Field  Museum  so  as 
to  be  able  to  recognize  them.  Small  collections  may  be  had 
cheaply  from  any  of  the  well-known  dealers  like  Ward's  Natural 
Science  Establishment^  Rochester,  New  York.     The  following 


70  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

tabulation  will  give  the  distinguishing  characters  of  the  com- 
monly occurring  minerals.  A  few  terms  need  definition  at 
the  outset  as  they  will  be  used  in  the  descriptions.  Certain 
minerals  like  calcite,  galenite,  and  feldspar  have  a  tendency  to 
split  easily  along  certain  planes  so  that  the  pieces  are  bounded 
by  smooth  surfaces.  This  is  known  as  cleavage  (Fig.  47). 
Galenite  cleaves  into  cubes,  feldspar  into  blocks  of  which  the 
opposite  faces  are  parallel  while  the  adjacent  faces  meet  in 
angles  that  are  either  a  little  more  or  a  little  less  than  right 
angles.  Fracture  is  the  surface  produced  when  a  mineral  breaks 
in  any  other  direction  than  along  its  cleavage  planes.  Thus  flint 
has  a  conchoidal  or  shell-shaped  fracture.  Streak  is  the  color 
given  when  the  mineral  is  rubbed  on  a  piece  of  unglazed  porcelain 
or  when  it  is  scratched.  Luster  is  the  appearance  when  light  is 
reflected  from  the  surface  of  the  mineral.  This  may  be  vitreous 
like  the  reflection  from  a  freshly  broken  piece  of  glass,  resinous, 
pearly,  silky,  etc. — terms  that  carry  their  own  meaning  plainly. 
One  of  the  chief  means  of  distinguishing  minerals  is  the  hardness. 
So  important  is  this  that  a  definite  scale  of  hardness  has  been 
agreed  upon.  Thus,  talc  has  a  hardness  of  i,  gypsum  2,  calcite 
3,  fluorite  4,  apatite  5,  orthoclase  6,  quartz  7,  topaz  8,  corundum 
9,  diamond  10.  For  ordinary  purposes  the  hardness  may  be 
indicated  in  a  less  exact  way,  still  the  numbers  given  after  each 
mineral  indicated  the  hardness  on  this  scale. 

Sedimentary  rocks. — As  we  have  seen  in  the  previous  chapters, 
sedimentary  rocks  are  originally  laid  down  as  beds  (i)  of  cal- 
careous materials  like  shells,  corals,  or  their  water-worn  frag- 
ments, (2)  beds  of  angular  rock  fragments,  (3)  of  gravel,  (4)  of 
sand,  (5)  of  clay,  or  (6)  of  plant  debris.  Later  these,  by  means 
of  cement,  by  pressure  or  by  heat,  acting  singly  or  in  unison,  are 
transformed  to  stone.  The  calcareous  material,  really  calcite  or 
calcium  carbonate,  makes  limestone  a  rock  that  can  be  scratched 
with  a  knife,  effervesces  with  an  acid,  and  often  contains  fossils. 
Angular  rock  fragments  cemented  together  form  a  breccia,  while 


THE  GLACIAL  PERIOD 


71 


if  the  fragments  are  waterworn,  as  gravel,  the  result  is  a  pudding 
stone  or  conglomerate.  The  sand  beds  transform  to  sandstone 
and  clay  to  shale,  readily  known  by  the  ease  of  its  separa- 
tion into  flakes.  The  plant  material  transforms  into  peat  and 
coal. 


'  Chalk,  0.5-2.5 


So  soft  they  can 
be  scratched  with    <J 
the  fingernail 


Chlorite,  1.5-4.0 


Gypsum,  1.5-2.0 


Easily  scratched 
with  a  knife 


Kaolin,  0.5-2.5 


Mica,  2.2-5.0 


Galenite,  2.5 


Serpentine,  2.5-4.0 


Calcite,  3 


White  to  gray,  dull,  crumbles  in 
fingers,  no  earthy  odor  when 
breathed  upon,  effervesces  with 
acid. 

A  green  mineral  of  pearly  to 
vitreous  luster  wath  greasy  feel- 
ing. It  usually  occurs  in  grains 
or  scales  in  basic  rocks. 

]\Iany  colors,  streak  always 
white.  Massive  (alabastine), 
fibrous  (satin  spar),  foliated  (if 
transparent  called  selenite). 

Many  colors,  streak  like  color. 
Feels  greasy.  Strong  clay  odor 
when  breathed  on.  Dull  to 
pearly  luster ;  brittle. 

Perfect  cleavage;  very  thin 
elastic  scales  can  be  obtained. 
The  black  sort  is  biotite;  the 
colorless,  gray,  or  pale  green, 
muscovite. 

Lead  gray,  streak  same.  ]\Ietal- 
lic  luster.  Very  heavy;  cleaves 
in  cubes. 

Color,  shades  of  green.  Luster 
greasy,  waxy,  or  earthy.  Feels 
smooth  or  greasy.  Compact  and 
amorphous,  making  a  rock  of 
the  same  name. 

Many  colors,  streak  white  to 
gray.  Always  cleaves  into 
rhombs.  Effervesces  in  dilute 
acid. 


72 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Easily  scratched 
with  a  knife 
(continued) 


Scratched  with  a 
knife  with  dif- 
ficulty 


Scratched  by 
quartz  but  not     { 
with  a  knife 


Sphalerite,  3.5-4.0 
(Zinc  blende) 


Yellow,  red,  brown,  black. 
Luster  resinous  when  yellow. 
Perfect  cleavage.     Brittle. 


Chalcopyrite,  3.5-4.0    Brass   yellow,   often   tarnished, 
(Copper  pyrite)  then        showing        iridescence. 

Streak  green-black.    Softer  than 
pyrite. 


Dolomite,  3.5-4.0 
(Pearl  spar) 


Mica,  see  above 
Limonite,  5.0-5.5 


Pyroxene  or 
Augite,  5-6 


Amphibole  or 
Hornblendes,  5-6 


Hematite,  5.5-6.5 


Feldspar,*  6.0-6.5 


Pyrite,  6.0-6.5 
(Fool's  gold) 


White,  gray,  green,  black. 
Streak  white.  Transparent  to 
translucent.  Crystals  curved 
like  saddles. 


Dark  brown,  streak  yellowish 
brown.  Often  fibrous;  if  earthy, 
color  is  yellow.  In  cubical 
crystals. 

Green  to  black.  Fracture  un- 
even to  conchoidal.  Usually  in 
short,  thick,  eight-sided  prisms. 
Cleavage  poor;  faces  meet  at  90°. 

Brown,  green,  or  black,  darker 
than  augite.  Fracture  as  above. 
Luster  pearly  on  cleavage  faces. 
Crystals  long,  slender,  six-sided, 
faces  finely  cross-striate.  Cleav- 
age faces  meet  at  1 24°. 

Cherry  red  to  iron  black;  streak 
red.  Metallic  luster,  massive  or 
fibrous  or  scaly. 

Many  colors,  streak  white. 
Cleavage  perfect,  faces  at  nearly 
right  angles.  Light  colored, 
orthoclase;    darker,  plagioclase. 

Brass  yellow,  tarnishes  brown. 
Streak  greenish  black.  Metal- 
lic luster.  Crystals,  cubes  or 
dodecahedra.  Harder  than 
chalcopyrite. 


THE  GLACIAL  PERIOD 


73 


As  hard  as 
quartz 


Olivine,  6.5-7.0 


Quartz,  7 


\ 


Green,  streak  white.  Trans- 
parent to  translucent.  Usually 
occurs  in  rounded  grains. 

Color  anything  from  black  to 
white.  Luster  vitreous  or  waxy 
in  chalcedony.  Fracture  con- 
choidal.  Crystals  six-sided 
prisms  ending  in  pyramids; 
blue,  amethyst,  banded  agate, 
onyx,  jasper.  In  massive 
nodules  occurs  as  flint. 


*  The  term  feldspar  stands  for  a  group  of  minerals.  Orthoclase  is  a  silicate  of 
aluminum  and  potassium — a  "potash-feldspar."  Its  cleavage  angle  is  a  right 
angle,  or  nearly  so.  It  is  usually  light  in  color,  white,  gray,  pink.  It  commonly 
occurs  in  rocks  in  which  quartz  is  present  fairly  abundantly  and  seldom  associates 
with  the  plagioclase  group.  This  plagioclase  group  includes  the  soda-Ume  feld- 
spars like  ohgoclase  and  labradorite.  The  plagioclases  have  an  oblique  cleavage 
angle,  and  certain  cleavage  faces  are  marked  with  numerous  fine  parallel  lines. 
The  plagioclases,  especially  the  ohgoclase  and  the  labradorite,  are  strongly  basic, 
seldom  occur  with  quartz  in  any  quantity,  often  are  present  with  augite  or  horn- 
blendes.    They  are  usually  dark  colored,  blues,  grays,  or  dull  reds. 

Igneous  rocks. — Sedimentary  rocks  are  largely  formed  from 
the  disintegration  of  previously  existing  rocks.  The  original 
rock  masses,  together  with  many  of  those  of  later  times,  were 
formed  from  the  cooKng  of  molten  material.  Such  are  igneous 
rocks.  When  lava  outpours  on  the  earth's  surface  in  volcanic 
regions  it  forms  rock  as  it  cools — volcanic  rock.  Such  rock 
usually  has  a  glassy  appearance  or,  if  it  is  crystalline,  the  crystals 
of  which  it  is  composed  are  small,  usually  indistinguishable,  for 
it  cools  too  rapidly  to  permit  a  thorough  crystallization.  Such 
volcanic  rocks  are  liable  to  be  quite  porous  on  account  of  the 
bubbles  of  gas  contained  in  the  molten  lava.  The  holes  formed 
by  the  included  bubbles  of  gas  may  later  be  filled  by  material 
deposited  by  percolating  water.  The  grains  of  such  deposited 
minerals  are  naturally  rounded,  and  the  rock  so  altered  is  known 
as  an  amygdaloid.  Molten  material,  on  the  other  hand,  that 
cools  off  slowly  way  down  below  the  surface  makes  coarse-grained 
rock,  the  crystals  being  large.  Such  rocks  are  called  plutonic, 
in  distinction  to  the  volcanic.     If  one  mineral  is  present  in  large 


74  ^-1  XATURALIST  IX  THE  GREAT  LAKES  REGIOX 

crystals  while  the  others  are  minutely  crystallized  or  more  or 
less  glassv.  the  rock  is  called  a  porphyry.  Plutonic  rocks  are 
dense,  since  formed  below  the  surface  under  great  pressure. 
Naturally  there  will  be  all  intergrades  between  the  plutonic  and 
the  volcanic  rocks,  since  the  cooling  lava  may  be  in  any  one  of 
many  situations  from  the  deep-seated  reservoir  to  the  surface 
flow. 

The  molten  material  differs  greatly  in  chemical  composition 
in  different  resiions  of  the  earth  and  even  two  successive  lava 
flows  from  the  same  volcanic  crater  ma}'  be  quite  unlike.  If  the 
lava  contains  much  silica  it  is  an  acid  lava  and  gives  rise  to  rocks 
with  many  silicates  and  much  free  sihca  or  quartz.  If,  on  the 
other  hand,  it  contains  strong  bases  Hke  calcium,  magnesium, 
and  iron,  it  is  a  basic  lava  and  the  resulting  rocks  will  contain 
little  free  silica  or  quartz,  though  they  will  contain  silicates  of 
the  basic  elements  mentioned  in  the  form  of  such  minerals  as 
plagioclase,  hornblende,  augite,  etc.  The  following  scheme  with 
the  brief  characterizations  that  follow  will  aid  in  the  determina- 
tion of  the  igneous  rocks  of  the  Chicago  area.  Nothing  hke  a 
complete  key  or  complete  descriptions  can  be  given  here,  and 
the  interested  student  will  secure  some  good  hthology  and 
studv  it  in  connection  with  the  specimens  of  typical  rocks  found 
in  the  museums.  This  scheme  will  help  the  observer  to  make  a 
start  on  interpreting  the  past  history  of  a  rock  from  its  present 
structure.  Five  rock  groups  are  given  in  the  order  of  their 
increasing  basidity  so  that,  from  left  to  right  in  the  series,  quartz 
is  becoming  less  abundant,  the  rocks  are  darkening  in  color  and 
increasing  ill  weight  as  the  plagioclases  replace  the  orthoclase, 
and  the  augite,  hornblende,  and  ohvine  at  the  end  largelv 
replace  even  the  plagioclase. 

Vertically  in  each  column  the  members  of  any  group  are 
named  from  distinctly  volcanic  rocks  down  to  those  that  are 
whollv  plutonic.  Going  down  the  column,  the  members  of  the 
famihes  are  less  porous,  less  glassy,  the  component  crystals  are 
constantlv  larger,  and  the  rocks  increase  in  speciflc  gravity. 


THE  GLACIAL  PERIOD 


IS 


The  granites  contain  quartz  and  orthoclase,  often  with  some 
hornblende,  mica,  or  augite.  (The  composition  of  the  gneisses 
is  the  same,  but  they  show  evidences  of  stratification — see  below.) 
If  any  one  or  two  minerals  are  especially  conspicuous,  the  granite 
is  named  accordingly,  as  hornblende  granite,  biotite-hornblende 
granite.  If  quartz  is  present  in  twin  crystals  in  a  matrix  of 
feldspar,  giving  an  appearance  of  cuneiform  writing  on  a  feld- 
spar background,  the  granite  is  pegmatite. 


Granite-Rhyolite  Group 

Syenite- 

Trachj'te 

Group 

Diorite-Andesite 
Group 

Gabbro-Basalt 
Group 

Peridote 
Group 

Quartz  and  Orthoclase 
Dominant 

Orthoclase 

Dominant: 

Quartz 

Absent  or 

Present  in 

Negligible 

Quantity' 

Plagioclase  and 
Hornblende  Dom- 
inant:  the  Latter 
Equaling  or  Ex- 
ceeding the  Feld- 
spar in  Amount 

Feldspar  (Lab- 
radorite)  and 
Pyroxene  Dom- 
inant:   the  Latter 
Equaling  or  Ex- 
ceeding the  Feld- 
spar in  Amount 

Feldspar 
Absent  or 
Nearly  So:- 
Hornblende, 
Pyroxene, 
Olivine,  the 
Dominant 
Minerals 

Rhyolite  pumice  (porous) 
Rhyoliteobsidian  (glassy) 

Granite  (crystalline) 

Other   minerals   may   be 
present  but  not  dom- 
inant   giving    biotite- 
granite,       hornblende- 
granite,  etc. 

Purphyritic  granite 

Pegmatite  granite 

Trachyte 
Cincludedin 
the  felsites) 

Syenite 

Andesite 
(included  in  the 
felsites) 

Diorite 

Diorite 

porphyry 

Basalt  tuff 
Basalt  breccia 

Basalt  dolerite 
Basalt 

Diabase 

(Olivine  diabase, 
olivine    gabbro, 
green  stone) 

Gabbro 

Diabase 
porphyry 

Peridotite 

Syenite  contains  an  abundance  of  orthoclase,  usually  the 
red  varieties  and  httle  or  no  quartz.  Hornblende,  mica,  and 
augite  may  any  one  or  all  be  present.  It  is  a  plutonic  rock  and 
therefore  usually  coarse  grained.  The  corresponding  volcanic 
rock  is  trachyte,  finer  grained,  more  porous,  anrl  lighter  in 
weight. 

In  the  diorites  the  dark  feldspars  are  predominant,  though 
sometimes  the  lighter-colored  plagioclases  are  abundant.     Quartz 


76  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

is  present  and  also  often  mica  and  hornblende  but  not  in  predomi- 
nating quantities.  The  diorites  are  plutonic,  the  corresponding 
volcanic  rocks  being  the  andesites. 

Gabbro  and  basalt  are  respectively  the  plutonic  and  the 
volcanic  members  of  the  next  family.  They  are  dark,  heavy 
rocks  with  labradorite  and  augite  as  the  predominant  minerals. 
Biotite,  chlorite,  magnetite,  pyrite,  olivine,  etc.,  may  be  accessory 
minerals.  The  gabbro  is  distinguished  from  the  diabase  by  its 
coarser  crystallization  and  the  large  quantity  of  pyroxene  it 
contains.  The  presence  of  chlorite  in  these  rocks  gives  them  a 
distinct  green  color  and  they  are  then  known  as  greenstones.  It 
is  difficult  to  distinguish  the  finely  crystalline  ingredients  of 
trachyte  and  andesite  in  the  field  sufficiently  to  distinguish 
them,  so  they  are  usually  called  collectively  ^'felsite"  as  dis- 
tinguished from  the  darker  and  heavier  basalt. 

Metamorphic  rocks. — Both  sedimentary  and  igneous  rocks 
may  be  altered  by  pressure,  crumpHng,  heat,  and  other  agencies, 
so  that  their  original  character  is  quite  changed;  such  rocks  are 
called  metamorphic  rocks.  Thus  the  limestones  become  crystal- 
hne  and  transform  to  marbles,  as  do  also  the  dolomites.  The 
effervescence  with  acid  still  distinguishes  them.  Dolomitic 
marbles  effervesce  only  in  strong  or  hot  acid,  the  ordinary  marble 
in  cold,  even  weak,  acid.  Sandstone  is  compacted,  the  sand 
grains  fused  to  make  quartzite — a  rock  that  may  have  any  color 
but  can  be  distinguished  by  its  hardness  and  conchoidal  fracture. 
It  is  not  as  vitreous  in  luster  as  is  quartz  itself,  and  shows  more 
or  less  its  granular  character.  Shales  are  changed  to  slates, 
recognized  by  their  easy  separation  into  thin  layers  like  roofing 
slate.  Sedimentary  rocks  composed  of  the  disintegration  of 
granites  are  by  metamorphosis  altered  to  schists  and  gneiss. 
The  latter  contains  the  same  minerals  as  granite,  but  there  is 
evidence  of  stratification  and  the  crystals  or  grains  of  the  com- 
pressed minerals  are  arranged  with  their  long  axes  in  one  plane. 
If  the  compression  has  been  so  great  as  to  flatten  the  component 
grains  or  crystals  into  scales,  the  rock  becomes  a  schist,  easily 


THE  GLACIAL  PERIOD  77 

broken  down  by  the  fingers,  especially  when  it  is  somewhat 
weathered.  Schists  are  commonly  named  from  the  mineral  that 
is  so  predominant  as  to  give  them  their  chief  character,  as  mica 
schist,  chlorite  schist,  etc. 

Granites  seem  also  to  have  been  transformed  directly  by 
metamorphic  agencies  into  gneiss  and  the  schists,  so  that  the 
end  result  of  metamorphism  on  such  igneous  rocks  and  on  sedi- 
mentary rocks  derived  from  them  may  be  identical. 


CHAPTER  V 


LAKE  CHICAGO  AND  ITS  OLD  SHORE  LINES 

S  THE  ice  sheet  finally  melted  (Fig.  48) 
and  retreated  farther  north  there  formed 
between  the  Valparaiso  Moraine  and 
the  front  of  the  glacier  a  lake,  called 
now  Lake  Chicago  (Fig.  50).  This  had 
its  outlet  through  the  gap  in  the  mo- 
raine known  as  the  Sag.  Two  streams 
from  the  lake — one  on  the  north,  one  on 
the  south  of  Mount  Forest  Island  (Fig.  53) — converged  to  this 
point.  It  was  probably  just  chance  inequalities  of  deposition 
that  determined  the  location  of  these  two  channels,  thus  form- 
ing Mount  Forest  Island,  but  the  Sag  was  likely  predetermined 
by  the  fact  that  here  ran  the  old  preglacial  valley,  a  deep  rock 
cut,  which  though  partly  filled  by  glacial  drift  still  made  a  distinct 
break  in  the  restraining  moraine.  Besides  Mount  Forest  Island 
another  isolated  mass  of  drift  stood  out  of  the  water  in  the 
Chicago  region,  namely  Blue  Island.  This  now  stands  above 
the  level  of  the  Chicago  plain,  once  the  old  lake  bottom,  as  a 
ridge  several  miles  long  and  one-half  mile  or  so  wide  stretching 
north  from  the  town  of  Blue  Island  to  Beverly  Hills.  The 
Rock  Island  suburban  fine  runs  close  to  its  east  side.  It  is 
encountered  as  an  abrupt  rise  on  Western  Avenue  about  Eighty- 
seventh  Street.  Anywhere  along  its  crest  one  looks  westward 
over  level  country,  old  lake  bottom,  to  the  distant  hills  of  the 
mainland  of  the  moraine  or  of  the  other  islands. 

Lake  Chicago  stood  at  one  level  for  a  long  time,  long  enough 
for  its  waves  to  eat  into  the  hills  along  its  shores  and  deposit 
extensive  beaches  of  sand  just  as  Lake  Michigan  is  doing  now 
along  its  present  shore  line.     The  highest  of  these  beaches  stands 

78 


LAKE  CHICAGO  AND  ITS  OLD  SHORE  LINES 


79 


at  a  level  some  sixty  feet  above  the  present  lake  level  (581  feet 
above  sea-level) .  It  is  by  following  these  plainly  marked  beaches 
that  the  position  of  the  shore  lines  of  early  Lake  Chicago  is 
determined  (Fig.  49).  On  the  map  (Fig.  53,  page  85),  can  be 
traced  the  shore  line  of  what  is  known  as  the  Glenwood  stage  of 


S 


"'"~^\. 


r:        \ 


■A 


I 


V-^ 


Fig.  48. — The  Wisconsin  ice  sheet  at  its  maximum.     Border  of  ice  represented 
by  heavy  feathered  hne. 

Lake  Chicago  (Fig.  50),  so  named  because  the  beaches  are  par- 
ticularly conspicuous  at  Glenwood  near  the  Industrial  School 
(Chicago  &  Eastern  Illinois  Railroad).  Northwest  from  this 
point  the  old  beach  runs  to  the  north  of  Homewood  (on  the 
Illinois  Central  Railroad)  about  a  mile  southwest  of  Rexford 
(on  the  Rock  Island)  to  the  north  of  Palos  Springs  (Wabash). 
It  is  plainly  seen  on  the  east  side  of  Mount  Forest  Island  (driv- 
ing west  on  Ninety-fifth  Street)  or  in  approaching  the  island  from 
Summit  on  the  Chicago  and  Joliet  interurban.      At  McCook 


8o 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


(Atchison,  Topeka  &  Santa  Fe  Railway)  and  to  the  north  of 
La  Grange  (Chicago,  Burhngton  &  Quincy  Railroad)  it  is  par- 
ticularly plain,  marked  by  steep  cHffs  that  have  been  more  or 
less  obscured  by  the  later  erosion  and  deposits.  Galewood 
and  Norwood  Park  are  on  it.     Thence  it  runs  northeast  and 


Fig.  49. — An  old  shore  line  of  Lake  Chicago 

terminates  in  the  Chicago  region  at  the  present  lake  shore  in 
high  bluffs  at  Winnetka. 

In  the  northern  part  of  Winnetka,  a  short  distance  south  of  the  pumping 
station,  the  cliff  and  terrace  of  the  Glenwood  stage  appear  halfway  up  the 
lake  cliff  and  extend  inland  with  pronounced  form  for  three-quarters  of  a 
mile.  The  terrace  is  about  55  feet  above  Lake  Michigan  ....  behind  it 
the  bluff  rises  to  a  height  of  20-30  feet,  with  a  very  steep  slope. 

To  the  east  of  Glenwood  the  shore  line  swings  southeast  toward 
the  lake,  passes  through  Furnessville,  runs  roughly  parallel  to 
the  present  shore,  and  abuts  on  the  shore  north  of  New  Buffalo. 
Notice  Desplaines  Bay  on  the  map  (Fig.  53),  into  which  the 
river  now  bearing  that  name  then  emptied.     See  also  the  sand 


LAKE  CHICAGO  AND  ITS  OLD  SHORE  LINES 


8i 


spit  at  the  mouth  of  this  bay  and  the  spits  at  the  ends  of  Blue 
Island.  There  was  a  great  branching  spit  running  south  and 
west  from  a  point  below  the  present  Winnetka  reaching  Niles 
Center,  which  spit  then  inclosed  Skokie  Bay  and  now  forms  the 
irregular  eastern  border  of  Skokie  Marsh.     The  waters  of  the 


,..{"*'•«— ^, 


W/* 


Fig.  50. — Lakes  Chicago,  Saginaw,  and  Maumee.  Lake  Maumee  at  an 
earlier  stage  was  more  extensive  and  outletted  down  the  Wabash  Valley  as  indicated 
by  dotted  lines.  All  three  lakes  now  discharge  through  the  Chicago  outlet.  This 
represents  about  the  Glenwood  stage  of  Lake  Chicago.  Modified  from  Leverett 
and  Taylor. 

lake,  moving  toward  the  outlet  or  currents  set  up  by  the  prevail- 
ing north  winds  checked  by  these  projecting  points,  dropped 
their  load  of  sediment  in  sand  bars.  The  wash  of  the  waves 
piled  the  material  up  above  the  lake  level  in  these  spits,  just  as 
they  are  formed  along  the  lake  shore  today  by  the  same  agencies. 
Lake  Chicago  continued  to  grow  in  size  as  the  front  of  the 
glacier  retreated.     But  what  is  more  important  from  our  interest 


82  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

in  its  alteration  of  local  topography,  it  changed  its  level,  dropping 
so  as  to  expose  the  bottom,  hereabout,  long  enough  for  vegeta- 
tion to  become  rank  and  form  extensive  peat  deposits.  This  was 
probably  due  to  the  uncovering,  by  the  retreat  of  the  ice,  of 
some  outlet  to  the  north,  at  a  considerably  lower  level  than  the 
Chicago  outlet.  These  peat  beds  are  found  in  excavations  such 
as  some  made  in  Rogers  Park  and  Evanston  several  years  ago, 
and  they  lie  on  the  beaches  of  the  Glenwood  stage.  They  are 
overlaid,  however,  by  deposits  of  the  next  or  Calumet  stage. 

The  lake  rose  again  as  possibly  the  glacier  advanced  tem- 
porarily and  again  covered  the  northern  outlet.  It  assumed  a 
level  about  twenty  feet  below  the  Glenwood  stage,  35-40  feet 
above  present  level  or  615-20  feet  above  sea-level.  It  again 
outletted  down  the  Desplaines  Valley.  Undoubtedly  during  the 
Glenwood  stage  the  valley  had  been  deepened  by  river  erosion. 
When  the  old  river  came  directly  from  the  front  of  the  glacier 
before  the  lake  was  formed  behind  the  Valparaiso  Moraine,  it 
was  heavily  charged  with  sediment  and  built  up  an  extensive 
valley  train  as  already  described.  But  when  the  river  became 
the  outlet  of  the  lake,  the  debris  held  by  the  glacier  was  dropped 
in  the  lake  and  the  outflowing  stream  was  clear,  ready  to  pick 
up  a  load  in  its  rapid  current  instead  of  making  a  deposit.  So 
from  the  time  Lake  Chicago  was  formed  the  outletting  stream 
had  been  working  to  erode  and  carry  away  the  silt,  sand,  and 
gravel  that  it  had  earlier  laid  down.  So  the  old  valley  formed 
by  the  preglacial  stream  that  came  down  the  broad  valley  where 
Lake  Michigan  lies  and  that  continued  down  what  is  now  the 
Desplaines  and  Illinois  valleys  was  filled  below  the  terminal 
moraines  by  the  valley  train  deposited  by  the  river  that  carried 
the  outwash  from  the  glacier  and  still  later  was  again  partly 
uncovered  by  the  outlet  of  Lake  Chicago. 

This  latter  erosion  was  apparently  checked  in  the  upper 
valley  when  the  river  encountered  a  rocky  ledge  below  the  sand 
and  gravel,  a  ledge  running  from  the  present  location  of  Lock- 
port  to  Joliet.     This  could  not  be  worn  away  rapidly  and  so  the 


LAKE  CHICAGO  AND  ITS  OLD  SHORE  LINES 


83 


level  of  the  lake  was  held  at  this  point  for  a  long  period.  During 
this  time  the  waves  and  currents  made  such  inroads  on  the  shore 
and  such  extensive  deposits  that  we  trace  them  today  in  a  series 
of  beaches  and  sand  bars  that  are  referred  to  this  Calumet  stage 
(Fig.  51).  The  course  of  the  Calumet  beach  can  be  traced  on 
the  map  (Fig.  53).     The  old  Desplaines  Bay  was  now  dry  land, 


.iM>>* 


,/ 


v 


.^'7" 


X 


Fig.  51. — Lake  Chicago  at  a  later  stage  (the  Calumet)  and  Lake  Warren. 
i\  tremendous  volume  of  water  must  have  been  going  through  the  outlet  past  the 
present  site  of  Chicago.     After  Leverett  and  Taylor. 

and  the  river  emptied  into  the  lake  near  the  present  site  of 
Lyons.  Salt  Creek  flowed  in  at  the  same  point.  Evidently  in 
the  lake  during  the  Glenwood  stage  a  great  sand  bar  had  formed 
in  the  lea  of  Blue  Island  and  a  smaller  one  out  in  the  south  channel 
of  the  outlet.  These  now  appear,,  the  former  as  a  portion  of  the 
large  island  that  included  Mount  Forest  Island  and  Blue  Island, 
the  latter  as  a  separate  islet,  Lanes  Island.     Note  the  long  sand 


84 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


spit  thrust  out  from  the  north  end  of  the  large  island,  its  elbow 
at  what  is  now  Summit,  sheltering  a  big  bay  then  probably  an 
extensive  marsh. 


Fig.  52. — Lake  Algonquin;  some  water  was  still  going  out  of  the  Chicago 
outlet  but  most  of  it  discharged  down  the  Trent  River  Valley  to  Champlain  Sea. 
Note  also  the  Hudson  and  Mohawk  estuaries.  This  represents  about  the  ToUeston 
stage.     After  Leverett  and  Taylor. 

Jefferson  Park,  Cragin,  Riverside,  Summit,  Washington 
Heights,  Oaklawn,  Dal  ton,  Thornton,  etc.,  are  all  on  the  old 
Calumet  beach.  Eastward  it  follows  closely  the  Glenwood  shore 
line  to  which  it  is  roughly  parallel.  There  was  a  great  offshore 
bar  built  up  at  this  stage.     This  now  terminates  near  Rose  Hill 


LAKE  CHICAGO  AND  ITS  OLD  SHORE  LINES 


85 


^v&dat<£ 


Fig.  53. — Map  of  the  Chicago  plain  and  adjacent  moraine. 
XXX    Land  bordering  Lake  Chicago  at  the  Glenwood  stage. 
/  /  /     Added  land  as  the  lake  dropped  to  the  Calumet  stage. 
W  \     Land  added  by  drop  to  ToUeston  stage. 

Land  added  by  drop  to  present  level  in  white. 

Sand  bars  dotted. 


86 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Cemetery  and  it  is  named  the  Rose  Hill  Bar.  It  runs  north  and 
east  through  Rogers  Park  and  Evanston,  where  for  six  miles  it  is 
followed  by  ''Ridge  Avenue."  It  rises  some  twenty  feet  above 
the  surrounding  plain.  The  outlet  to  the  north  of  Mount  Forest 
Island  was  apparently  partially  blocked,  possibly  by  the  Summit 
sand  spit  and  the  others  that  were  formed  offshore,  so  that  at 
this  Calumet  stage  the  main  outflow  was  through  the  present 
Lake  Calumet  region,  past  the  south  end  of  Blue  Island  along 
the  outlet  to  the  south  of  Mount  Forest  Island.     The  great 


-i. 

i 

> 

P 

J 


Fig.  54. — When  the  outlet  of  Lake  Chicago  was  chiefly  to  the  south  of  Mount 
Forest  Island  the  swift  river  current,  carrying  rocks,  wore  grooves  and  potholes 
in  the  limestone  bed.  They  are  seen  here  where  excavations  for  the  new  canal 
freshly  expose  the  bed  rock. 

potholes  in  the  bedrock  here,  uncovered  in  the  construction  of 
the  Calumet  branch  of  the  Drainage  Canal,  worn  by  rocks  in 
the  grip  of  eddies,  indicate  a  large  and  rapid  river  (Fig.  54). 

The  rock  barrier  in  the  bed  of  the  outletting  river  at  Lock- 
port  which  held  the  lake  at  the  Calumet  level  could  not  stop  the 
lowering  of  the  valley  floor  indefinitely.  The  obstruction  was 
made  up  of  the  inclined  strata  of  Niagara  limestone  against 
which,  near  Joliet,  lay  much  softer  shale.  The  river  had  no 
difficulty  in  cutting  away  these  shales,  but  the  Hmestone  was  a 
more  difficult  proposition.  However,  the  limestone  strata  were 
so  inclined  that  the  river  rushed  down  the  incline,  which  was  at 


LAKE  CHICAGO  AND  ITS  OLD  SHORE  LINES  87 

the  downstream  end  of  the  obstruction,  forming  a  rapids  with 
violent  current  that  worked  furiously  at  cutting  out  the  rock. 
Gradually  the  rapids  ate  their  way  through  these  strata  until 
finally  they  reached  the  upper  end  of  the  rock  dam.  The  rock 
barrier  once  removed,  the  stream  rapidly  cut  through  the  gravel 
of  the  old  valley  train  to  the  lake  and  another  drop  in  the  lake 
level  occurred,  of  some  fifteen  feet.  A  reference  to  the  m^ap 
(Fig.  51)  will  show  that  through  the  Chicago  outlet  was  flowing, 
during  the  Calumet  stage,  not  only  the  waters  from  the  front  of 
the  Michigan  lobe,  but  also  that  from  much  of  the  Saginaw  and 
Erie  lobes.  This  great  stream  was  undoubtedly  a  vigorous 
worker. 

So  Lake  Chicago  assumed  a  new  level,  the  Tolleston  stage 
(Fig.  52),  some  twenty  feet  above  present  lake  level  or  about  six 
hundred  above  sea-level.  It  held  it  long  enough  to  cut  a  new 
shore  line  and  deposit  extensive  beaches.  The  location  of  these 
Tolleston  beaches  is  shown  on  the  map  (Fig.  53). 

The  main  Tolleston  beach  abuts  on  the  lake  shore  not  far 
north  of  the  campus  of  Northwestern  University  which  it  crosses 
from  North  Gate,  running  inland  beneath  Herck  and  University 
Halls.  It  runs  through  the  city  on  the  east  side  of  Chicago 
Avenue  and  in  South  Evanston  is  followed  pretty  closely  by 
Clark  Street.  Thence  it  continues  south  of  Calvary  Cemetery, 
through  Rogers  Park  and  Rose  Hill,  bordering  the  old  Rose  Hill 
Bar.  From  Garfield  Park  to  Hawthorne  it  is  very  plain.  It  is 
easily  traced  east  from  Summit,  thence  southeast  through 
Auburn  Park  and  Burnside.  Stony  Island,  an  island  new  born 
at  this  Tolleston  stage  of  the  lake,  appears  here  close  oft'shore, 
and  the  Tolleston  beach  is  very  plain  on  its  northern  side.  From 
Burnside  the  beach  runs  south  through  Kensington,  then  swings 
east  and  follows  quite  closely  the  general  present  contour  of  Lake 
Michigan. 

It  will  be  noted  that  both  north  and  south  outlets  on  either 
side  of  Mount  Forest  Island  are  pretty  well  closed  by  the  end 
of  this  stage,  for  a  great  sand  spit  had  been  built  all  across  the 


88  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

north  outlet,  a  natural  embankment  later  used  by  railroads 
entering  Chicago  from  the  east.  The  Desplaines  no  longer 
emptied  into  the  lake  but  was  flowing  south  through  the  channel 
of  the  old  outlet.  Below  the  main  ToUeston  beach  are  one  or 
two  others  showing  apparently  considerable  fluctuation  at  this 
stage.  It  is  thought  that  Lake  Chicago  had  become  a  part  of 
the  greater  Lake  Algonquin,  which  included  Lakes  Superior, 
Michigan,  Huron,  and  more  (Fig.  52).  It  was  discharging 
through  Lake  Erie.  Probably  some  of  these  Tolleston  beaches 
were  the  shore  lines  of  this  greater  lake.  There  is  evidence  that 
the  level  of  the  water  in  the  lakes  dropped  considerably  below 
its  present  level  when  for  awhile  the  great  lakes  discharged 
through  Georgian  Bay,  the  river  Trent  across  Ontario  to  an 
arm  of  the  sea  in  northern  New  York  (Champlain  Sea)  (Fig. 
52).  But  finally  through  a  gradual  rise  in  these  northern  areas 
the  level  of  the  water  rose  to  the  present  grade,  and  the  discharge 
through  Lakes  Huron  and  Erie  was  resumed. 

It  is  interesting  to  note  how  human  affairs  are  determined 
by  events  that  transpired  hundreds  of  thousands  of  years  ago, 
long  before  man  had  even  appeared  on  the  earth.  The  route 
followed  by  two  great  transcontinental  railroads  in  entering 
Chicago — the  Chicago  &  Alton  Railroad  and  the  Atchison, 
Topeka  &  Santa  Fe  Railway — is  that  of  the  old  outlet  of  Lake 
Chicago,  and  its  location  was  determined  by  the  presence  of 
the  preglacial  valley  whose  position  w^as  fixed  by  the  lay  of  the 
rock  strata  deposited  in  Paleozoic  time.  The  same  thing  is 
true  elsewhere.  The  Lackawanna  and  the  New  York  Central, 
in  leaving  New  York  City  for  the  West,  follow  the  valleys  of 
old  rivers  that  carried  the  main  outwash  from  the  glacier,  and 
their  location  was  fixed  by  the  lay  of  rock  strata  that  were 
deposited  aeons  ago.  Lake  Michigan,  Desplaines  River,  and 
the  Illinois  River  were  made  a  great  north  and  south  artery  of 
travel  when  the  old  preglacial  valley  continued  past  the  present 
site  of  Chicago  down  what  later  became  the  Illinois  Valley.  And 
when  the  Valparaiso  Moraine  happened  to  so  deposit  that  the 


LAKE  CHICAGO  AND  ITS  OLD  SHORE  LINES  89 

portage  from  the  Chicago  River  to  the  Desplaines  was  fixed 
within  the  present  city  limits,  Chicago's  site  was  practically 
settled.  Even  the  locations  of  our  fashionable  residence  sec- 
tions, streets,  railroad  approaches,  recreation  parks,  and  sewage 
system  were  more  or  less  completely  settled  by  the  deposits  of 
moraines,  locations  of  old  beach  lines,  sand  spits,  and  dunes  of 
the  old  glacial  lake. 


CHAPTER  VI 
DISTRIBUTION  AND  ADJUSTIVIENT 

HE  purpose  of  this  and  the  succeeding 
chapters  is  to  show  how  the  physio- 
graphic features  of  the  Chicago  region, 
the  origin  of  which  has  been  outhned  in 
the  preceding  pages,  determine  the  dis- 
tribution of  plants  and  animals,  not 
directly  but  by  shaping  in  large  meas- 
ure the  interplay  of  those  factors  that 
do  condition  the  plant  and  animal  life.  The  chief  factors  for 
plants  are  available  moisture  and  light;  for  animals,  the  oxy- 
gen supply,  food,  nest-forming  materials,  light,  heat,  currents, 
foes,  etc.  Furthermore,  plants  and  animals  are  nicely  adjusted 
in  structural  peculiarities  and  habits  to  the  complex  of  these 
Hmiting  factors,  and  it  will  be  the  aim  of  succeeding  pages  to 
point  out  also  some  of  these  adjustments. 

It  is  a  matter  of  common  knowledge  that,  the  world  over, 
there  is  a  zonation  of  life.  The  vegetation  of  the  tropics  is 
totally  unlike  that  of  the  temperate  regions,  and  the  life  of  the 
latter  zones  is  quite  different  from  that  of  the  arctic.  The  ascent 
of  a  mountain  carries  the  traveler  through  a  succession  of  life- 
zones,  from  the  luxuriant  growth  about  the  base  through  scant 
vegetation  and  disappearing  animals  to  a  bleak  and  almost 
uninhabited  peak. 

Temperature  is  on  the  w^hole  a  very  great  factor  in  the  deter- 
mination of  the  abundance  and  character  of  both  plant  and 
animal  forms.  Locally  its  effect  is  to  settle  the  distribution  in 
time  rather  than  fix  the  place  in  which  animal  or  plant  shall 
grow,  for  naturally  there  is  no  very  great  dift'erence  in  tempera- 
ture in  the  various  parts  of  the  Chicago  area  unless  it  be  a 

go 


DISTRIBUTION  AND  ADJUSTMENT 


91 


•contrast  between  the  deeper  parts  of  lakes  and  their  surface 
waters.     But  there  is  a  seasonal  distribution  of  both  plants  and 


Fig.  55. — Spring  flowers  of  the  forest  floor:  Upper  left,  spring  beauty,  Claylonia 
virginica;  upper  right,  toothwort,  Dentaria  laciniata;  lower  left,  Dutchman's- 
breeches,  Dicentra  cucullaria;  lower  right,  yellow  adder's-tongue,  Erythronium 
americanum. 


92  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

animals  locally.  Thus  we  have  a  distinct  spring  flora.  NoteJ 
for  instance,  the  early  annuals  of  the  oak  woods— spring 
beauties,  anemone,  toothwort,  trilHum,  hepatica,  Dutchman's- 
breeches,  dogtooth  violet,  bloodroot — these  and  others  like  them 
are  all  plants  that  are  up  and  in  blossom  before  the  trees  are  in 
leaf  to  shade  them  (Fig.  55).  They  get  through  with  their  life- 
cycle — bud  and  flower  and  fruit — here  on  the  forest  floor  while 
the  great  trees  overhead  are  just  beginning  to  stir  with  the  thrill 
of  the  spring  awakening.  These  plants  have  found  an  unoccupied 
part  of  the  season,  and  they  make  the  best  of  it.  They  all 
possess  underground  stems  loaded  with  stored  food  that  enable 
them  to  make  this  very  rapid  growth,  then  slowly  accumulate 
during  months  of  shade  a  supply  sufficient  for  the  next  spring. 
Moreover,  in  many  cases  their  tender  leaves  that  appear  while 
frosts  are  still  common  are  clothed  in  dense  hair — a  veritable 
fur  coat  to  protect  them.  They  are  replaced  later  by  other 
plants  that  have  become  adjusted  to  growing  in  the  dense 
shade  of  the  summer  under  the  trees.  Those  mentioned  need 
abundant  sunlight  to  carry  through  their  brief  program  of  rapid 
maturation. 

The  temporary  grassy  ponds  that  result  from  the  melting 
of  the  snows  are  the  homes  of  a  group  of  animals  that  appear 
marvelously  indifferent  to  the  low  temperatures  of  early  spring; 
they  thrive  in  the  ice-rimmed  water.  There  is  the  so-called 
fairy  shrimp,  Euhranchipus  (Fig.  566?),  not  a  shrimp  at  all,  though 
its  airy  grace  and  mysterious  appearance  make  the  rest  of  the 
name  appropriate  enough.  It  is  a  reddish-brown  crustacean, 
a  quarter  of  an  inch  long  when  first  seen,  but  growing  rapidly 
to  an  inch  in  length.  It  swims  on  its  back,  waving  nineteen 
pairs  of  feathery  legs  to  propel  itself.  The  head  bears  a  pair  of 
staring  compound  eyes.  The  egg  sacks  of  the  females  are  con- 
spicuous early,  and  strings  of  slender  eggs  can  be  seen  in  the 
semi-transparent  body  on  their  way  to  be  discharged  into  the 
icy  water.  The  adults  soon  die;  the  whole  hfe-history  occupies 
only  a  month  or  so  of  early  spring.     The  eggs  lie  dormant  in 


Fig.  56. — Some  fresh-water  crustaceans  a,  Asellus,  the  water  sow  bug; 
b,  Gammarus,  the  bender;  c,  Palaemonetes,  the  true  shrimp;  d,  Eiibranchipiis,  the 
fairy  shrimp;  e,  Canthocampns;  f,  Cyclops;  g,  Cypris,  side  and  top  views;  h, 
Daphnia,  the  water  flea. 


94  A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

the  bottom  of  the  pond.  When  it  dries  up  they  dry,  too. 
They  may  blow  about  in  the  wind  to  new  locations.  They 
freeze  with  the  winter  cold;  in  fact  they  w^ill  not  hatch  until 
they  have  dried  out  and  frozen.  And  so  they  are  ready  to 
start  the  next  generation  in  the  ponds  of  the  following 
spring. 

Other  inhabitants  of  these  ponds  are  the  red  water  mite, 
Hydrachna;  a  tiny  crustacean  with  a  bivalve  shell,  looking  like 
a  very  small  clam  until  it  sticks  out  its  feathery  swimming 
organs  {Cypris  marginata)  (Fig.  56^) ;  the  water  sow  bug  (Fig. 
56a);  the  bender  (Fig.  56^),  a  crustacean  that  swims  rapidly 
with  even  speed,  but  which  when  taken  in  the  hand  bends  and 
unbends  rapidly;  Cyclops,  Daphnia  (Fig.  56/,  //);  some  clado- 
cerans;  the  green  fiat  worm.  Here,  too,  one  may  find,  if  low 
prairie  is  near,  the  spring  peeper,  Chorophiliis  nigritus,  that 
marsh  tree  frog  whose  clear  peep  is  almost  like  a  bird  note. 
It  takes  to  the  ponds  to  lay  its  eggs  almost  before  the  ice  is'gone. 
The  eggs  are  laid  in  gelatinous  clusters  that  fill  the  palm  of  the 
hand  and  in  the  pond  are  attached  to  the  grasses  along  the 
margins  or  to  sticks  in  the  shallow  places. 

The  frog's  egg  is  admirably  adapted  to  hatch  on  these  cold 
days.  It  is  covered  with  a  transparent  jelly  layer  that  retains 
the  sun's  heat  like  the  glass  of  a  greenhouse.  It  has  a  black 
upper  surface  that  absorbs  heat  like  a  black  dress.  The  egg  is 
laid  so  early  that  it  avoids  many  of  the  insect  larvae  that  would 
later  prey  upon  it.  It  is  inconspicuous,  its  black  upper  surface 
harmonizing  well  with  the  dark  pond  bottom  when  seen  from 
above,  and  its  light  under  surface  with  the  clouds  when  seen  from 
below,  so  that  it  easily  escapes  detection. 

Just  as  there  are  an  early  spring  flora  in  the  woods  and  a 
spring  fauna  in  the  temporary  ponds,  so  there  are  early  spring 
plants  and  animals  in  the  swamps,  on  the  dunes  and  in  other 
typical  localities.  In  each  place  the  spring  types  are  followed 
by  early  summer  types,  by  midsummer  and  autumnal  species. 
One  need  only  call  attention  to  this  seasonal  distribution  to  have 


DISTRIBUTION  AND  ADJUSTMENT 


95 


it  substantiated  by  many  commonplace  facts.  Thus  we  name 
many  insects  by  the  time  of  their  appearance,  as  May  flies, 
June  beetles,  the  fall  army  worm,  etc.  Just  as  the  appearance 
of  the  robins  and  the  bluebirds  marks  early  spring,  so  we  think 


,V     20-  60% 

:::  eo-  8o% 


•    «        •       • 

•      •       • 

80-100% 

100-110% 

■ \ 

1^ 

m 

110-130% 
130-150% 

fc^ 

\}T 

^ 

i$ 

150-180% 

% 

M 

180+     % 

Fig.  57. — Map  showing  relation  of  rainfall  to  evaporation  in  Eastern  United 
States.  Unmarked  lower  left,  rainfall  20  per  cent  or  less  of  the  evaporation. 
The  other  markings  are  explained  on  the  figure. 

of  midsummer  as  butterfly  time,  and  the  chirp  of  the  cricket  as 
the  first  voice  of  fall. 

In  the  local  place  distribution  of  plants,  moisture  is  of  prime 
importance,  or  rather  the  ratio  between  rainfall  and  evaporation. 
If  the  water  supply  greatly  exceeds  the  evaporation,  then  the 
plant  grows  in  a  pond  or  marsh  and  is  designated  a  hydrophyte. 


96 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


At  the  other  extreme  are  the  xerophytes,  plants  growing  where 
the  evaporation  tends  greatly  to  exceed  the  water  supply.  The 
open  dunes  give  an  excellent  illustration  of  such  conditions. 


Unmarked  (lower,  left) — desert 


Semidesert 


T»>>';i;'V,'   Transition  grass  land  to  deciduous 
■■■"'■•'"■'■'       forest 

-  ^      Deciduous  forest 


■  Western  xerophytic  fore-^t,  dwarf 
junipers,  etc. 

"tJlC^  Transition  desert  to  grass  land 


Viv'/U    Grass  land 


^  Transition  to  evergreen  forest 

4   A     Evergreen  forest.    No  attempt  is  made 
^        to  distinguish  northern  and  southern 


\^  1^   Swamp 

Fig.  58. — jNIap  of  vegetation  areas  in  Eastern  United  States.     After  Shreve 

The  great  majority  of  plants  grow  where  there  is  neither  excess 
nor  dearth  of  water  and  are  known  as  mesophytes.  This  ratio 
of  evaporation  to  rainfall  is  a  very  important  factor  in  deter- 


DISTRIBUTION  AND  ADJUSTMENT 


97 


mining  plant  distribution  on  a  large  scale  as  well  as  locally. 
This  is  apparent  from  a  comparison  of  the  accompanying  maps, 
one  (Fig.  57)  showing  the  ratio  of  rainfall  to  evaporation  in  the 
various  parts  of  the  United  States,  the  other  (Fig.  58)  the  forest, 
prairie,  and  plains  areas.  The  general  coincidence  of  forest 
distribution  and  of  the  areas  occupied  by  prairies  and  plains 
with  the  areas  of  a  decreasing  rainfall  is  very  striking. 

That  physiographic  features  must  affect  the  moisture  content 
of  the  soil  is  evident  on  reflection.     A  poorly  drained  area 


90        1 00 


Intensity   of  evaporation 

Standard,  open  garden,  Normal  School 

Sta.  Ill,  b.  Mixed  prairie  and  young  forest 

Sta.    II,  a.  Grassy  area,  Panicum 

Sta.    II,  a.  Grassy  area,  Euphorbia 

Sta.  IV,  a.  Upland,  open  woods 

Sta.  III.  a.  Silphium  on  black  soil 

Sta.    II,  a.  Colony  of  5.  laciniatum 

Sta.  IV,  b.  Ravine  slope,  open  woods 

Sta.   IV,  c.  Dense  climax  forest  cover 


Fig.  59. — Diagram  of  the  relative  evaporation  in  different  prairie  and  forest 
habitats,  showing  the  great  reduction  in  evaporation  with  the  development  of  a 
closed  forest  canopy  of  a  climax  forest;    Charleston,  Illinois.     After  Adams. 

develops  swamps,  bogs,  and  wet  prairie.  A  rock  surface  is  prone 
to  be  xerophytic;  so  too  will  be  the  steep  side  of  a  clay  bluff. 
On  the  other  hand,  the  side  of  a  rock  ravine  may  furnish  hydro- 
phytic  conditions,  for  the  sunhght  penetrates  so  little  that  the 
temperature  is  low,  the  evaporation  is  slight,  and  even  though 
water  be  not  abundant,  it  may  be  so  well  conserved  as  to  be 
adequate  to  moisture-loving  plants.  The  accompanying  dia- 
gram (Fig.  59),  modified  from  Adams,  will  show  how  great  differ- 
ences there  are  in  rate  of  evaporation  in  contiguous  regions,  and 
also  that  temperature  differences,  while  not  great,  may  still  be 
sufficient  to  influence  animal  and  plant  distribution. 


98 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Many  marked  structural  peculiarities  and  adaptive  life- 
habits  go  along  with  the  ability  of  the  plant  to  endure  drought 
or  excessive  moisture.  Since  the  loss  of  water  goes  on  largely 
through  the  leaves,  the  leaf  surface  of  the  xerophyte  is  often 
reduced  in  proportion  to  its  volume  by  the  leaf  being  needle 
shaped  rather  than  fiat  and  thin.  The  leaf  surface  may  be 
covered  with  hairs,  and  so  evaporation  becomes  reduced,  or  the 


Fig.  6o. — The  cactus,  Opuntia  Rafinesquii,  in  fruit  in  the  dunes 

surface  may  be  covered  with  impervious  wax;  such  a  weed  as 
the  mullein,  growing  in  open  w^aste  territory,  is  a  familiar  example 
of  the  former,  and  the  glossy-leaved  plants  of  the  ground 
stratum  in  the  pine  dunes — like  the  wintergreen,  shinleaf,  and 
prince's  pine — are  examples  of  the  latter,  as  is  also  the  very 
common  field  milkweed.  The  oak  leaf  and  that  of  the  cotton- 
wood  are  both  thicker  and  glossier  than  the  leaf  of  the  hard 
maple  or  beech  that  grows  in  the  mesophytic  conditions  of  the 
climax  forest.     The  leaf  stem  or  underground  portions  of  the 


DISTRIBUTION  AND  ADJUSTMENT 


99 


plant  may  be  thick  and  succulent,  storing  up  water  in  time  of 
plenty  to  use  in  time  of  drought.  The  common  cactus  of  the 
dunes  is  a  good  illustration  (Fig.  60).  The  plants  growing  where 
moisture  is  lacking  often  develop  an  extensive  superficial  root 
system  to  gather  up  the  dew  and  the  showers  before  the  water 
has  time  to  dissipate  or  sink  deep  into  the  parched  soil.  One 
can  pull  out  fine  stringHke  roots  in  the  open  dunes  that  run  just 
below  the  surface  for  hundreds  of  feet  to  the  tree  or  bunch  grass. 


Fig.  61. — The  six-lined  lizard,  Cnemidophorus  sexlineatus 

Many  of  the  animals  of  the  open  dunes  are  in  hiding  during 
the  day,  some  of  them  like  the  burrowing  spider,  Lycosa  wrightii, 
in  holes  that  run  down  to  the  cool  and  moist  soil  layers.  The 
surface  of  the  sand  is  covered  in  the  early  morning  with  the  fresh 
tracks  of  many  animals  that  have  been  out  during  the  cool 
of  the  night  to  satisfy  their  needs,  while  the  same  areas  are 
apparently  uninhabited  by  day.  The  six-lined  lizard  (Fig.  61), 
that  like  the  cactus  is  a  desert  form  left  in  this  sandy  oasis 
by  the  lake,  excretes  its  uric  acid  in  solid  form,  a  conservation  of 
water  common  to  many  reptiles. 


lOO       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


The  light  relation  determines  not  so  much  where  the  plant 
grows  as  its  habits  of  growth  in  a  locality  fixed  chiefly  by  the 
water  supply.  Thus,  some  plants  are  said  to  be  shade  loving. 
They  are  found  forming  the  ground  stratum  in  the  forest  with 
other  plants,  a  shrub  stratum,  over  them,  plants  less  able  to 
endure  the  shade,  though  they  in  turn  are  overgrown  by  a  tree 
stratum  whose  members  insist  on  getting  up  into  the  full  glare  of 
the  sunhght  (see  Fig.  297).     The  entire  association  is  due  to  the 

lOO+X 

ABOIC  rOttCST 


jMM55;^i7,:m''55V  ' 


'■55-/.?  1 


SURFACE        SURFACE 


SURFyiCF  SURFJC€ 


DAMP      FOREST     qAK  FOREST       GLAOC 
PRAIRIE  MARGIN 


SuRFACe 

PUMAX  FOREST 


RA  VINE 

Fig.  62. — Diagram  showing  relative  evaporating  power  of  air  as  influenced 
by  prairie  and  forest  vegetation.     After  Adams. 

mesophytic  conditions  that  all  need,  and  probably  the  stratifica- 
tion is  due  quite  as  much  to  the  relative  amounts  of  evaporation 
(see  Fig.  62)  as  to  the  varying  light  intensity.  How  dim  the 
light  is  in  the  ground  layers  of  the  forest  becomes  apparent  in  try- 
ing to  take  pictures  in  the  beech-maple  woods ;  the  exposure  meter 
indicates  an  intensity  one-twentieth  that  of  the  surrounding 
open  pastures;  so  undoubtedly  the  light  factor  is  to  be  regarded 
as  of  great  importance.  This  is  made  more  evident  when  the 
fact  is  recognized  that  the  same  shade-loving  plants  found  on 
the  forest  floor  are  also  often  found  in  the  rock  ravine.  Thus,  the 
clearweed,  the  touch-me-not,  and  such  characteristic  ferns  as  the 
beech  fern,  the  fragile  fern,  and  the  spleenwort,^5/?/gwzww  angusti- 
folium,  are  common  in  both  locations  (Figs.  270,  273,  274,  395). 


DISTRIBUTION  AND  ADJUSTMENT 


lOI 


Some  plants  growing  in  the  intense  light  of  the  marsh  and 
prairie  have  very  interesting  habit  adaptations  that  avoid  the 
intense  light  and  heat  of  midday.  The  upright  position  of 
the  leaf  in  the  grasses,  the  iris,  and  cat-tails  accomplishes  this, 
for  the  edge  or  tip  of  the  leaf  is  presented  to  the  midday  glare, 
the  broadside  of  the  leaf  catch- 
ing the  less  intense  early 
morning  or  late  afternoon  sun. 
The  common  lettuce  (Fig.  6^,) 
and  the  compass  plant,  Sil- 
p Ilium  laciniatum,  both  have 
the  habit  of  turning  their 
leaves  so  that  they  are  in  a 
vertical  position  at  noon,  the 
tips  north  and  south,  one  edge 
up,  the  other  down,  so  show- 
ing the  edge  rather  than  the 
broad  side  to  the  noon  light. 

No  single  line  of  demar- 
cation in  the  distribution  of 
animals  is  as  clear  cut  as  that 
between  the  water  animals — ■ 
the  water  breathers  as  they 
are  commonly  called — and  the 
air  breathers.  Of  course  in  each  case  the  oxygen  in  the  air  is  the 
important  element  taken,  but  in  the  water  forms  this  is  absorbed 
from  the  supply  dissolved  in  the  water,  while  the  others  take  it 
directly  in  the  respired  air.  Probably  in  the  course  of  evolution 
most  animal  as  well  as  plant  life  was  aquatic  in  its  origin.  The 
hydrophyte  and  the  hydrozooid  are  the  primitive  types,  and 
these  early  forms  lived  not '  only  where  water  was  abundant 
but  they  lived  under  water.  Such  an  existence  necessitates  on 
the  part  of  complex  forms  some  special  device  for  taking  the 
needed  oxygen,  for  every  living  thing  must  have  this  essential 
gas  since  it  is  only  by  constant  oxidation  that  the  energy  supply 


Fig.  63. — A  compass  plant,  wild  let- 
tuce, Lacliica  scariola. 


I02        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

is  maintained,  by  means  of  which  all  live  and  move  and  have 
their  being.  The  simple  plants  and  animals  can  absorb  the 
oxygen  and  give  off  the  carbon  dioxide,  together  with  other 
waste  products  of  combustion,  directly  through  the  moist  skin. 
But  the  higher  types  have  needed  to  develop  gills  or  similar 
structures  and  some  sort  of  circulation  to  take  the  gas  to  the 
working  cells.  The  more  complex  plants  growing  totally  sub- 
merged have  their  leaves  dissected  so  that  they  consist  of  numer- 
ous threadlike  filaments  or  else  they  are  long  and  narrow, 
ribbon-Uke,  so  that  every  part  of  the  leaf  is  near  the  oxygen 
supply  of  the  water.  See,  for  instance,  the  leaf  of  water  milfoil, 
of  bladderwort,  of  hornwort,  all  common  to  our  ponds  or  streams 
(Fig.  64).  The  water  buttercup  at  times  grows  submerged,  again 
only  partly  so.  The  submerged  portions  have  leaves  that  are 
finely  dissected,  the  aerial  portions  the  usual  buttercup  leaf.  It  is 
interesting  to  note  that  the  animal  gill  is  built  on  the  same  general 
plan  as  the  submerged  leaf,  a  series  of  filaments,  sometimes 
branched.  In  the  animal  these  are  provided  with  vessels  that  take 
up  the  needed  oxygen  and  carry  it  to  the  distant  internal  organs. 
The  transition  from  water-inhabiting  animal  to  land  dweller 
is  seen  in  the  life-history  of  our  common  toad.  The  eggs  are 
laid  in  the  water,  hatch  into  tadpoles  that  are  vegetarians,  and 
breathe  by  means  of  gills.  In  time  these  deyelop  legs,  resorb 
their  tails,  come  out  on  to  the  land,  replacing  the  gills  by  lungs 
and  feeding  entirely  on  insect  food.  When  the  first  sea  worms 
crawled  out  of  the  water  to  make  their  burrows  on  land,  a  wealth 
of  food  was  awaiting  them  in  their  virgin  hunting  ground,  for 
the  land  was  largely  unoccupied  by  animal  life.  When  some 
primitive  fish  crawled  out  on  the  mud  banks,  using  its  fins  as 
legs — and  there  is  one  that  does  this  still — it  was  rewarded  by 
a  lot  of  food  which  others  of  its  kind  could  not  get.  But  soon 
the  earth  swarmed  with  life,  and  even  the  air  supported  a  full 
complement.  Then,  apparently  some  of  the  animals  that  earlier 
forsook  the  water  for  the  land  or  air  went  back  again  to  hunt  in 
the  water,  and  no  more  interesting  series  of  adaptations  is  to 


c  d  e 

Fig.  64. — Leaves  of  water  plants:  a,  Anacharis;  h,  Ceratophyllmn  or  hornwort; 
c,  Caboma  or  water  moss;  d,  Myriophyllum  or  milfoil;  e,  Utricularia,  or  bladderwort. 


I04        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

be  found  than  those  enabhng  the  land  animals  to  hve  in  the 
water.  Insects  likely  evolved  from  land  forms  and  never  did 
live  in  the  water  until  some  of  them  took  to  it  as  a  secondary 
consideration.  They  are  primarily  air  breathers,  taking  the 
air  in  through  numerous  spiracles  on  the  sides  of  the  body  to  a 
system  of  internal,  ramifying  air  tubes.  When  they  took  to  the 
w^ater  they  were  forced  to  strange  devices.  Some  diving  beetles 
like  Dytiscus  and  some  of  the  Hemiptera  like  the  giant  water 
bug  carry  down  a  supply  of  air  between  the  concave  back  of  the 
abdominal  portion  and  the  overlying  convex  wing  covers.  The 
spiracles  or  breathing  pores,  which  on  most  insects  are  on  the 
sides  of  the  abdomen,  are  now  on  its  top,  which  is  the  bottom  of 
the  air  chamber.  Other  animals  enmesh  enough  air  in  the  hairs 
of  body  and  legs  to  last  them  awhile;  they  seem  to  carry  a  film 
of  silver  over  the  parts,  the  air  film  reflects  so  much  light.  The 
common  water  scorpion  has  a  long  air  tube  at  the  posterior  end 
of  the  body  so  it  can  stand  submerged  on  some  aquatic  plant  and 
still  breathe  through  its  air  tube,  the  open  tip  of  which  is  kept 
at  the  surface  (Fig.  212). 

Even  the  spiders  have  taken  to  the  Vv^ater.  Some  common 
locally  walk  on  the  water  and  count  it  no  miracle,  they  even  run 
with  celerity,  capturing  flies  and  gnats  out  of  the  reach  of  their  less 
fortunate  kind.  One,  the  diving  spider,  hunts  under  water,  even 
spins  its  silken  nest  below  the  surface.  This  nest  is  cup  shaped,  the 
opening  down,  and  the  adult  spider  carries  down  to  the  eggs  and 
young  a  supply  of  air  enmeshed  in  the  hair  of  abdomen  and  legs 
that  it  scrapes  off  so  as  to  keep  the  cup  full  until  the  young  are 
old  enough  to  come  to  the  surface  for  their  own  supply  (Fig.  213). 

Some  insect  larvae  are  also  air  breathers  and  must  come  to 
the  surface  to  renew  their  supply.  Such,  fortunately  for  us,  are 
the  mosquito  larvae  that  we  may  exterminate  by  oiHng  the  ponds 
and  ditches  where  they  breed,  so  they  cannot  get  to  the  top. 
Such,  as  also  the  adult  insects  already  described,  are  really  air 
breathers.  But  there  is  a  host  of  insect  larvae  that  are  true 
water  breathers,  taking  in  the  oxygen  by  means  of  gills.     These 


DISTRIBUTION  AND  ADJUSTMENT  105 

may  be  platelike  structures,  as  in  the  damsel-fly  nymph,  or  they 
may  be  filamentous,  as  in  the  larvae  of  stone  fly,  May  fly,  or 
whirligig  beetle  (Fig.  212).  In  the  nymph  of  the  common  dragon 
fly  respiration  is  accomplished  through  the  wall  of  the  large 
intestine,  and  a  special  chamber  for  the  purpose  is  attached  to 
this  organ,  the  water  flowing  into  it  through  the  anal  opening. 

Snails,  clams,  and  fish  have  largely  remained  water  breathers, 
as  have  also  most  of  the  crustaceans.  Some  of  the  latter  like 
the  land  sow  bug  have  taken  to  damp  situations  on  land,  as  under 
old  logs  and  under  the  bark  of  stumps.  The  common  chimney 
crayfishes  live  much  of  the  time  out  of  the  water  near  the  tops 
of  their  burrows,  still  breathing  however  by  gills  (see  Fig.  379). 
Many  snails  have  come  to  be  land  dwellers,  always  in  damp 
situations,  though,  but  still  they  breathe  by  means  of  a  lung  as 
do  even  some  of  the  pond  forms.  Locally  we  have  no  fish  that 
live  out  of  the  water,  but  there  are  such  that  run  around  on  the 
mud  banks  or  even  climb  logs  and  inclined  tree  trunks  in  search 
of  insects;  and  in  some— the  African  lung  fish,  for  example — 
respiration  is  accomplished  in  the  air  by  means  of  the  modified 
swim  bladder,  an  organ  that  in  most  fish  is  a  float,  but  that 
serves  in  this  one  the  purpose  of  a  primitive  lung. 

We  do  have  examples  in  abundance  of  the  higher  vertebrates 
that  have  taken  to  the  water  as  a  hunting  ground  and  must 
modify  their  air  breathing  to  suit  the.  exigencies  of  the  case.  The 
frogs,  turtles,  some  snakes,  such  birds  as  the  grebes,  and  mammals 
like  the  muskrat  are  cases  in  point.  The  muskrat  has  ring 
muscles  about  its  nostrils  by  the  contraction  of  which  he  can 
close  these  openings  when  he  dives.  The  bones  of  grebes  have 
spongy  interiors  as  indeed  do  those  of  all  birds.  The  lung 
cavities  connect  with  these  porous  portions  so  the  air-supply 
that  can  be  taken  below  water  is  increased.  The  frog  spends 
its  winter  entirely  submerged,  hibernating  in  the  mud  at  the 
bottom  of  the  pond.  Its  mouth  and  nostrils  are  then  closed 
air  tight  and  what  respiration  goes  on  is  accomplished  through 
the  skin,  a  return  to  the  primitive  method. 


io6        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

The  amount  of  oxygen  contained  in  the  water  plays  a  very 
important  part  in  determining  the  distribution  of  the  water- 
breathing  species.  Some  can  Kve  only  where  there  is  an  abun- 
dance of  it.  Thus,  some  sorts  of  insect  larvae,  snails,  and  fish 
are  found  only  in  the  rapids  of  the  brook  where  the  constant 
turmoil  of  the  water  brings  in  an  abundant  oxygen  supply;  such 
will  not  live  at  all  in  the  nearby  quieter  reaches.  Other  kinds,  on 
the  contrary,  can  get  on  very  well  even  in  the  stagnant  pools 
where  the  decomposing  organic  debris  is  abundant,  the  oxygen 
content  low,  and  the  carbon  dioxide  content  high.  The  details 
of  such  distribution  will  be  considered  in  a  later  chapter  on  the 
brook  community. 

Another  exceedingly  important  factor  in  determining  the  dis- 
tribution of  animals,  probably  the  most  important  locally,  is  the 
location  of  the  food  supply.     Thus  one  sort  of  animal  may  feed 
on  a  single  species  of  plant  or  those  of  one  genus,  and  then  its 
distribution  is  determined  by  that  of  its  food  plant.     Anosia 
plexippus,  the  monarch  butterfly,  is  found  the  world  over  only 
where  the  milkweed  grows.     This  is  not  only  because  the  butterfly 
feeds  upon  its  blossoms,  by  no  means  exclusively,  however,  but 
because  the  young  feed  on  the  leaves.     Similarly  the  young  of  the 
anglewing  butterflies  are  reared  on  violet  leaves  and  locally  they 
are  abundant  along  the  borders  of  wood  or  on  moist  prairies  where 
the   violet   abounds.     One   hunts   for   the   pawpaw   butterfly, 
Papilio  ajax,  and  for  the  spicebrush  swallowtail,  Papilio  Iroilus, 
only  in  the  cHmax  forest,  though  of  course  occasionally  one  may 
wander  some  distance  from  its  customary  habitat.     This  mobility 
of  animal  Ufe  as  contrasted  with  the  fLxity  of  most  plants  makes 
it  more  difficult  to  fix  the  hmits  of  animal  associations;  and  yet, 
making  due  allowance  for  the  wanderer,  they  are  quite  as  definite. 
So  important  is  the  food  plant  that  one  could  almost  name  animal 
communities  after  the  plants  that  serve  as  centers  of  attraction, 
either  directly  as  a  food  or  indirectly  by  harboring  animals  that 
are  the  prey  of  the  carnivorous  types.     The  common  milkweed 
has  such  a  host  of  visitors — nearly  four  hundred,  though  not  all 


DISTRIBUTION  AND  ADJUSTMENT 


107 


in  any  one  locality — that  the  group  may  be  collectively  called 
the  milkweed  association.  So  we  may  speak  of  the  com  plant 
association,  a  group  of  plants  and  animals  that  directly  affect  the 
crop  and  so  assume  large  practical  significance.  Such  a  grouping 
of  animals  would,  of  course, 
make  as  many  societies  as 
there  are  food  plants,  a  multi- 
plication of  detail  that  fortu- 
nately is  obviated  by  the  fact 
that  plants  are  grouped  into 
societies  by  the  interplay  of 
certain  factors,  so  that  the 
animals,  as  far  as  the  food 
factor  is  concerned,  tend  to 
a  like  grouping.  This  will 
appear  in  detail  in  the  suc- 
ceeding chapters. 

This  relation  of  a  specific 
animal  to  a  particular  plant 
as  its  source  of  food  is  the 
foundation  of  some  of  the 
most  remarkable  adaptations 
to  be  found  in  nature.  The 
nectar  of  the  flowers,  much 
sought  by  insect  epicures,  is 
available  only  to  a  favored 
few.  Thus  the  common  weeds, 
butter  and  eggs  and  the  closed 
gentian  (Fig.  65),  both  bear  blossoms  that  shut  with  so  firm  a 
spring  that  only  the  strong  and  heavy  bumblebee  can  force  an 
entrance.  He  pays  for  their  hospitality  by  carrying  the  pollen 
so  essential  to  flower  fertilization  and  seed  production.  A  rosin 
weed  common  on  the  prairie,  Silphium  perfolialum,  bears  water 
cups,  ensheathing  the  stem,  formed  by  the  bases  of  the  leaves 
(Fig.  66) .     These  effectually  keep  crawling  insects  away  from  the 


Fig.  65. — The  closed  gentian,  Gcnliana 
Andrewsii. 


io8       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


blossoms  so  the  nectar  may  be  reserv^ed  for  the  flying  forms  that 
alone  servx  the  plant  in  pollination.  The  wild  pink  accomplishes 
the  same  object  by  rings  of  sticky  substance  exuded  on  its  stem 
at  the  nodes.  Flowers  with  long  tubular  corollas  like  evening 
primrose,  trumpet  vine,  and  Jimson  weed  are  so  deep  that  only 
insects  with  long  sucking  tubes  like  the  moths  and  butterflies 
can  reach  the  nectar,  though  sometimes  the  bumblebee  bites 
through  the  base  of  the  blossom  and  steals  a  meal.     The  hound's 

tongue,  whose  blossom  is  the  color  of  aging 
meat  and  w^hich  has  a  corresponding  odor, 
is  \isited  chiefly  by  flies  that  seem  partic- 
ularly adapted  to  enjoy  its  sweets  and  to 
transfer  its  pollen.  Sometimes  a  flower  is 
so  constructed  as  to  require  the  presence 
of  a  single  sort  of  insect  to  take  out  and 
carry  its  pollen;  such  is  the  case  with 
the  Yucca,  grown  as  an  ornamental  plant 
in  our  gardens  and  dependent  on  the 
yucca_  moth  that  is  always  associated 
with  it. 

On  the  blossom  clusters  of  a  fall  aster 
Fig.  66.— Cup  formed   ^^^]^    white-ray    flowers    and    \^ellow-disk 

about  the  stem  at  base  of  r  r     i  •  i         i         i 

leaf  petioles,  Silphium  flowers  One  often  finds  a  spider  that  has  a 
perfoliatum,  the  cup   yellow  body  and  white  legs.     Lying  thus 

concealed  by  its  harmonious  coloring,  it 
pounces  on  the  visiting  flies  and  so  secures  its  food. 

There  is  a  plant  louse  or  aphid  that  feeds  on  the  roots  of  our 
common  field  corn.  It  in  turn  furnishes  to  the  common  brown 
ant  a  fluid  excretion  that  serv^es  as  food  and  seems  to  be  highly 
prized.  The  ant  takes  the  eggs  of  the  aphid  into  its  burrows  in 
the  fafl,  rears  the  aphids,  and  in  the  spring  sets  them  out  to  feed 
on  the  tender  shoots  of  weeds  until  such  time  as  the  corn  germi- 
nates, when  they  are  transferred  by  the  ants  to  the  corn  roots. 

Light  is  an  important  factor  in  the  distribution  of  animals. 
Thus  many  species  inhabiting  the  ground,   the  subterranean 


DISTRIBUTION  AND  ADJUSTMENT  109 

fauna,  are  repelled  by  strong  light.  Such  is  the  case  with  the 
earthworm.  An  electric  flash  light  will  reveal  in  the  garden  or 
forest  at  night  many  earthworms,  their  anterior  ends  projecting 
from  the  burrows  in  search  of  decayed  leaves,  their  chief  article 
of  diet.  The  bright  light  causes  their  instant  withdrawal.  The 
sow  bug,  woods  cockroach,  bark  beetles,  wood  borers,  slugs,  and 
many  spiders  prefer  the  dark  or  the  dim  light  and  are  to  be  found 
by  day  only  in  their  retreats  under  bark  or  stones  or  in  similar 
situations. 

There  is  a  whole  host  of  water  forms  that,  while  minute,  are 
the  chief  source  of  fish  food.  They  are  so  sensitive  to  light  that 
they  migrate  from  the  deeper  waters  to  the  surface  and  back 
again  as  the  Hght  wanes  or  brightens.  There  are  protozoa, 
rotifers,  and  many  tiny  crustaceans  in  this  association,  together 
with  a  variety  of  microscopic  plants  on  which  they  feed.  Alto- 
gether this  assemblage  of  living  things,  a  floating  or  free  swim- 
ming population,  is  known  as  plankton.  In  Turkey  Lake,  Indiana, 
at  the  time  of  its  maximum,  it  constitutes  more  than  one-half 
per  cent  by  volume  of  the  water;  in  Lake  Michigan  scarcely  a 
thousandth  as  much.  Such  a  density  as  that  in  Turkey  Lake 
means  more  than  fifty  million  organisms  to  the  quart.  Kofoid , 
found  in  the  Illinois  River  at  the  State  Biological  Station  about 
five  millions  per  quart,  a  million  of  which  were  animals.  Since 
tiny  fish  feed  on  these  organisms  they  follow  the  plankton  in  its 
diurnal  migration,  and  the  larger  fish  that  are  carnivorous  go  along 
too.  Any  fisherman  knows  that  trolling  for  bass  is  best  in  the 
early  morning  or  late  afternoon,  and  that  luck  is  better  on  a 
cloudy  day  than  a  bright  one.  The  plankton  and  the  small 
fry  are  near  the  surface  in  the  dim  light,  and  so,  too,  are  the  big 
fellows  that  feed  upon  them  and  that  may  by  mistake  try  the 
fisherman's  lure. 

Nesting  sites  and  nest-building  materials  are  factors  that 
help  to  determine  animal  distribution.  The  muskrat  and  his 
northern  relative,  the  beaver,  are  found  along  the  streams,  not 
alone  because  his  food  is  here  abundant,  but  also  because  the 


no       A  NATUILiLIST  IN  THE  GREAT  LAKES  REGION 


material  for  the  house  is  here.  The  cKff  swallow  prefers  natural 
rock  walls  beside  the  water  to  which  to  afhx  his  mud  jugs  for 
nesting  purposes.  The  woodpecker  must  live  in  the  forest,  not 
only  because  his  food  is  there,  but  also  because  he  needs  a  tree 
for  his  nest  site.  The  marsh  wren  away  from  the  marsh  would 
probably  find  it  more  difficult  to  find  substitute  for  the  rushes 
she  uses  to  make  her  globular  nest  (see  Fig.  345)  than  she  would 
to  secure  her  insect  food.  Shelford  found  that,  giving  the  tiger 
beetle,  which  is  found  on  the  clay  bluffs  along  the  shore,  oppor- 
tunity in  the  laboratory  to 
deposit  eggs  on  steeply  in- 
clined and  level  clay,  sand, 
and  loam,  in  all  cases  the 
females  chose  the  clay  in 
which  to  deposit  the  eggs 
and  that  two-thirds  of  the 
holes  made  in  oviposition 
appeared  on  the  steep  clay. 
Complex  adaptations,  both 
of  structure  and  of  habit, 
have    arisen  in   connection 

Fig.  67.— Digger  wasp  of  the  Dunes,  with  the  USe  of  specific  loca- 
Bcmbcx  spimlae,  X4.  Below,  the  front  tions  or  of  particular  mate- 
foot,  Xio.  j^^jg    -j^    j^gg^    building.     A 

single  instance  must  here  suffice.  In  the  cottonwood  zone 
in  the  Dunes  there  is  a  digger  wasp  that  excavates  a  burrow 
in  the  sand  in  which  to  deposit  its  eggs  (Fig.  67).  The 
wasp  is  a  httle  larger  than  a  house  fly.  It  stands  on  the 
sand  to  dig,  and  proceeds  very  much  like  a  dog  digging  a 
hole  in  the  ground.  It  uses  the  forefeet  as  excavating  tools 
and  throws  the  dirt  out  from  under  its  body  between  the 
hmd  legs.  It  makes  the  dirt  fly,  too,  at  a  great  rate.  The 
animal's  front  foot  is  expanded  and  provided  with  bristles  along 
the  edge  that  further  enlarge  it  and  make  quite  an  efficient 
digging  tool.     The  burrow  usually  starts  on  a  sloping  hillside 


DISTRIBUTION  AND  ADJUSTMENT  in 

and  runs  in,  inclining  downward  from  the  mouth.  It  is  three 
or  four  inches  long.  In  digging  it  the  wasp  cannot  throw  the 
sand  out  from  the  far  end  at  once,  but  must  move  it  several  times, 
about  an  inch  each  time,  by  the  method  already  described. 
While  digging  she  comes  to  the  mouth  of  the  burrow  frequently, 
backing  out  always,  stands  still  a  moment,  and  goes  back  to 
work  unless  some  inadvertent  movement  of  the  observer  scares 
her,  when  she  flies  away  to  return  shortly  if  all  is  quiet.  The 
burrow  completed,  the  mouth  is  closed,  the  wasp  throwing  the 
earth  into  it  from  all  sides,  changing  her  position  repeatedly  to 
do  this.  Then  she  flies  off  to  secure  insects  with  which  to  stock 
her  excavation.  She  apparently  uses  dead  flies  chiefly,  which 
she  secures  from  the  dead  insects  washed  up  by  the  waves  along 
shore.  On  her  return  with  a  fly  she  drops  it  on  the  sand  near 
the  nest  site.  She  runs  around  erratically  to  locate  the  hole 
exactly,  uncovers  the  opening,  quickly  seizes  the  fly,  and  goes 
in  with  it.  She  reappears  almost  immediately,  covers  the  open- 
ing, and  flies  off  for  another.  When  four  or  five  flies  are  secured 
she  remains  in  the  burrow  somewhat  longer  with  the  last, 
emerges  backward  as  usual,  and  then  spends  considerable  time 
closing  the  opening  and  pawing  the  sand  about  until  all  trace 
of  her  work  is  obHterated.  Presumably  the  egg  or  eggs  are  laid 
in  the  burrow,  possibly  on  the  flies  that  are  to  serve  as  food  for 
the  growing  grubs.  The  most  remarkable  thing  in  this  whole 
stor)^  is  that  when,  after  many  days,  the  young  female  emerges 
from  her  gravelike  nursery  she  shortly  proceeds  to  dig  a  hole, 
stock  it  with  flies,  lay  the  eggs,  and  cover  up  the  nest  with  con- 
summate skill,  yet  she  has  received  no  instruction,  has  not  even 
seen  the  job  done.  Somehow  in  her  nervous  system  is  registered  • 
the  racial  instinct,  and  she  goes  through  the  whole  performance 
unerringly,  untaught. 


CHAPTER  VII 

THE  DUNES  AND  THEIR  PLANTS 

O  REGION  about  Chicago  manifests  such 
rapid  changes  in  physiographic  features 
as  the  dune  region,  and  nowhere  are 
the  effects  of  these  changes  more  ap- 
parent on  the  distribution  of  plants  and 
animals.  It  is,  therefore,  a  very  favor- 
able region  for  an  initial  study  of  plant 
and  animal  societies. 
It  extends  from  Gary  east  along  the  shore  of  the  lake  and 
well  up  the  eastern  shore.  The  area  is  from  a  quarter  of  a  mile 
to  several  miles  in  width  and  with  occasional  interruptions  where 
cla}^  bluffs  come  to  the  shore  it  is  a  hundred  miles  or  so  long. 
In  general  it  consists  of  a  succession  of  sandy  ridges  that  are 
roughly  parallel  to  the  lake.  These  vary  in  height;  the  crests 
of  the  tallest  stand  200  feet  above  the  level  of  the  lake.  Those 
nearest  the  shore  are  quite  barren,  but  those  farther  back  are 
increasingly  covered  with  trees  and  associated  shrubs  and 
herbs.  Between  these  steep-sided  hills  are  valleys  occupied 
often  with  long  narrow  ponds  or  with  marshes  and  swales  (see 
chap.  ix). 

The  effective  storm  winds  in  the  Chicago  region  come  out 
of  the  northwest.  These  pile  up  the  waves  that  erode  the  shores 
and  heap  the  sand  upon  the  beaches.  After  a  heavy  storm  a 
newly  formed  sand  bar  ofi'shore  is  a  common  sight  (Fig.  68). 
Since  the  shores  of  Lake  Michigan  lie  north  and  south,  the  eff'ect 
of  these  furious  winds  is  to  tear  down  the  lateral  shores  by  wave 
action  and  drive  the  debris  by  currents  gradually  southward. 
Ultimately  this  debris  will  be  pulverized  by  the  waves,  deposited 
in  bars,  and  thrown  up  in  sandy  beaches  on  the  east  side  and  the 


112 


THE  DUNES  AND  THEIR  PLANTS  113 

south  end  of  the  lake.  These  same  stiff  winds  pick  up  this  sand 
after  it  has  dried  out  on  the  shore,  and  carry  it  inland.  So  the 
winds  that  blow  vigorously  inshore  are  sand  laden,  ready  to 
scour  with  the  vigor  of  a  sandblast  but  also  ready  to  deposit 
wherever  their  velocity  is  checked. 

Clumps  of  growing  plants  are  the  most  effective  agencies  in 
checking  the  wind  and  causing  deposition.     Wherever  the  bunch 


Fig.  68. — A  newly  formed  sand  bar 

grass  is  growing,  or  where  a  grapevine  or  a  low  juniper  spreads 
its  interlaced  branches  on  the  surface  of  the  sand,  there  the  sand- 
laden  air  driving  into  the  mass  of  vegetation  is  checked  and  so 
deposits  some  of  its  burden  before  it  escapes  (Fig.  69).  But  such 
sand  heaps  are  small.  The  interlaced  stems  and  branches  of 
young  trees  and  shrubs  make  the  most  successful  device  for 
enmeshing  the  sand  and  forcing  the  wind  to  deposit  it  in  larger 
dunes.  A  clump  of  red-osier  dogwood  or  a  thick  stand  of 
cottonwoods  are  buried  quite  rapidly,  and  did  they  not  grow 


114       ^  NATURALIST  IN  TEE  GREAT  LAKES  REGION 

more  rapidly  than  the  sand  piles  up,  they  would  be  completely 
engulfed  by  the  drifting  sand. 

A  dime,  therefore,  usually  starts  on  some  low-lying  area  near 
the  shore  where  the  sand  is  sufficiently  moist  to  allow  many 
Cottonwood  seeds  to  germinate,  yet  far  enough  from  the  storm 
beach  so  the  seedhngs  are  not  uprooted  by  the  heavy  waves. 
Such  a  low,  moist  germination  bed  is  known  as  a  panne  (Fig.  70) . 
That  cottonwoods  are  the  predominant  growth  in  such  a  locality 
is  due  to  the  fact  that  these  poplars  are  the  commonest  trees  in 


Fig.  69. — Small  dunes  held  by  bunch  grass  and  prostrate  juniper,  Jiinipcnis 
horizontalis. 


the  neighborhood,  as  will  be  explained  shortly,  and  also  because 
their  seeds  are  small,  tufted  with  a  silky  pappus  that  insures 
their  ready  transportation  by  the  wind.  Other  plants  that  might 
take  kindly  to  such  a  place,  like  the  red-osier  dogwood,  have 
seeds  that  are  not  wind-blown.  A  wagon  crossed  a  low  area 
near  the  lake  west  of  Mineral  Springs  in  the  spring  of  191 2.  The 
ruts  left  in  the  moist  sand  faciUtated  the  lodgment  of  poplar 
seeds,  and  the  next  year  a  double  row  of  seedlings  was  found  and 
photographed  on  the  spot  (Fig.  71).  In  two  years'  time  a  dune 
was  forming,  as  is  seen  from  the  photograph  of  the  same  spot 
in  191 5.  In  fact,  in  that  time  the  sand  had  piled  up  somewhat 
over  two  feet,  and  now  it  is  shoulder-high. 


THE  DUNES  AND  THEIR  PLANTS  115 

We  shall  have  occasion  to  remark  constantly  in  the  succeed- 
ing chapters  on  the  adaptation  of  particular  plants  and  animals 
to  specific  environmental  conditions.  Indeed  it  is  to  be  the 
major  purpose  of  the  remainder  of  the  book,  to  show  how  plants 
and  animals  are  grouped  in  societies  that  are  determined  by  the 
ability  of  the  several  organisms  to  endure  similar  conditions.  In 
the  dune  region  the  associations  are  roughly  parallel  to  the  shore 
and  for  plants  succeed  each  other  in  the  following  order:  (i)  the 


Fig.  70. — A  panne  near  Miller,  Indiana 

beach  association;  (2)  the  fore-dune  association;  (3)  the  cotton- 
wood  association;  (4)  the  pine  association;  (5)  the  black  oak 
association;  (6)  the  mixed  oak  association;  (7)  the  oak-hickory 
association;    (8)  the  maple-beech  association. 

Along  the  border  of  the  lake  is  the  wave-swept  beach,  where 
no  Kving  thing  can  maintain  permanent  residence.  Even  here 
there  are  transients  among  the  animals  as  will  be  explained 
shortly.  There  is  a  stretch  of  wind-blown,  shifting  sand,  the 
storm  beach  pounded  by  breakers  raised  by  the  heavy  winds; 
this  also  is  nearly  barren  of  life.  A  few  annuals  grow  here  dur- 
ing the  summer  when  severe  storms  rarely  occur.     The  sea  rocket 


ii6        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


^"4^11^1 


#' 


f-%*.. 


«">% 


■f 


.4 


II 


?>* 


^    r 


>i 


,^ 


Fig.  71. — Upper:  A  double  row  of  cottonwood  seedlings  near  Mineral  Springs, 
Indiana.  Lower:  The  same  two  years  later.  Note  the  forming  dune  is  nearly 
knee-high. 


72 


75r 


73 


60 


Figs.  72-80:  Fig.  72. — Sea  rocket,  Cakile  edentula;  Fig.  73. — Bugseed, 
Corispcrmnm  hyssoplfolium;  Fig.  74 — Beach  pea,  Lathyrus  maritimiis;  Fig.  75. — 
Cinquefoil,  Potentilla  Anserina;  Fig.  76. — ^Wormwood,  Artemisia  caudata;  Fig. 
77. — Rye  grass,  Elymus  canadensis;  Fig.  78. — Winged  pigweed,  Cydolonia  atriplici- 
foliiim;  Fig.  79. — Green  milkweed,  Aceraies  viridiflora;  Fig.  80. — Seaside  spurge, 
Euphorbia  polygonifolia. 


Ii8        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


and  bugseed  are  the  most  common  plants.     Back  somewhat 
farther  the  pioneers  of  vegetation  begin  to  get  a  foothold  in  the 

permanent  beach  association; 
such  are  the  beach  pea,  beach 
cinquef  oil,  wormwood,  cocklebur, 
and  sand  thistle. 

The  sea  rocket  (Fig.  72)  is  a 
plant  with  succulent  stems  and 
thick  fleshy  leaves.  The  flowers 
are  light  purple,  appearing 
like  those  of  the  garden  radish. 
The  pods  are  two-jointed.  The 
bugseed  (Fig.  73)  is  an  annual 
with  slender  awl-shaped  leaves. 
The  fruits  are  numerous,  small, 
hard,  and  have  a  winged  mar- 
gin. The  beach  pea  (Fig.  74)  is 
a  stout  trailing  plant  with  leafy 
expansions  or  stipules  at  the 
base  of  the  compound  leaves. 
Fig.  8 1. -Leaf  and  one  fruit  of    The  flowers  are  large,  an  inch  or 

cocklebur,  Xanthiiim  echinatmn.  more  long,   purple.      The  beach 

cinquefoil,  Potentilla  canadensis,  is  a  plant  with  palmately  com- 
pound leaves,  having  three  to 
five  leaflets.  It  multiplies  by 
runners  somewhat  as  a  straw- 
berry plant  does.  The  blos- 
soms are  somewhat  like  those 
of  the  strawberry,  though 
small  and  pale  yellow  to  white. 
Another  species,  Potentilla 
Anserina  (Fig.  75),  is  found  in 
the  same  locality.  Wormwood 
(Fig.  76)  is  a  plant  with  a  finely  dissected,  densely  hairy  leaf. 
It  is  very  bitter  to  the  taste.     Cocklebur  (Fig.  81)  is  so  common 


1 

Fig.  82. — Sand  thistle,  Cirsium  Pitcher i 


THE  DUNES  AND  THEIR  PLANTS 


119 


a  weed  everywhere  that  its  burrs  and  coarse  leaves  are  famihar. 
The  sand  thistle  (Fig.  82)  is  a  pale,  hairy  thistle  with  very  weak 
prickers  and  heads  of  cream-colored  blossoms. 

Then  comes  the  fore-dune  association  (Fig.  83)  including,  in 
addition  to  the  foregoing,  the  sand  reed  grass,  marram  grass, 
rye  grass  (Elymus)  winged  pigweed,  green  milkweed,  seaside 
spurge,  mullein,  sand  cherry,  and  the  furry  willow.  The  sand 
reed  grass  (Fig.  84)  grows  in  clumps  from  underground  running 
root  stalks.  It  bears  its  seeds  in  a  spreading  cluster.  Where 
its  leaves  sheath  the  stalk  they  bear  a  ring  of  short  hairs. 


"»-«►_."■' 


,ji^-''' 


"^ 


Fig.  St,. — The  beach,  the  storm  beach,  fore-dune,  pine  and  oak  associations. 


The  Cottonwood  zone  is  missing  here. 


Marram  grass  (Fig.  85)  also  grows  in  clumps,  springing  from 
underground  running  root  stalks,  and  bears  its  seeds  on  a  dense 
spike.  Its  leaves  are  tipped  with  a  long  slender  point.  There 
is  no  ring  of  hairs  on  the  leaves  where  they  clasp  the  stem.  Rye 
grass  (Fig.  77)  or  wild  rye  looks  like  growing  grain.  The  leaves 
are  broad.  The  seedlike  fruits  grow  in  a  spike,  each  one  bearing  a 
long  bristle  or  awl.  The  winged  pigweed  (Fig.  78)  is  a  much- 
branched,  coarse  annual.  Very  small  scattered  flowers  give  it  a 
characteristic  appearance  shown  in  the  illustration.  Green  milk- 
weed (Fig.  79)  has  milky  juice  and  broad,  glossy,  almost  sessile 
leaves.     Its  flowers  are  green,  and  their  hoods  have  no  crests 


120       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Fig.   84. — Long-leaved     sand     reed, 
Calamovilfa  longifolia. 


such    as    are    present    in    common    field    milkweed.      Seaside 
spurge  (Fig.  80)  has  milky  juice.     The  leaves  are  long  and 

narrow,  with  squarish  ends.  It 
is  a  much-branched  plant,  low 
and  spreading.  Mullein  is  the 
common  weed  known  by  its 
thick  leaves,  densely  covered 
with  hair  which  gives  them  a 
velvety  feel.  It  is  also  known 
as  velvet  plant.  Sand  cherry 
(Fig.  86)  has  a  smooth,  reddish 
bark  characteristic  of  cherry 
trees.  This  bark  peels  off  in 
thin  sheets  and  is  marked  by 
horizontal  lenticels.  The 
leaves  are  long,  narrow,  larger 
at  the  outer  end  than  at  the 
stem,  and  the  fruit  is  a  good-sized  cherry,  one-half  inch  or  more 
in  diameter,  that  is  quite  tasty  though  somewhat  acrid.  The 
furry  willow  (Fig.  87),  Salix 
svrticola,  is  a  low  shrub  with 
twdgs  and  lea\'es  covered  wdth 
dense  hair.  The  leaves  have 
large  stipules.  The  broad- 
leaved  wdllow,  Salix  glauco- 
phylla,  is  also  found  on  the 
fore-dune  zone.  It  is  also  a 
shrub  with  leaves  that  are 
dark  green,  shiny  above,  and 
light  green  below. 

Next  comes  the  cottonwood 
zone  (Fig.  88).     The  cotton- 
wood  tree  is  the  one  tree  that 
can  stand  the  open  dunes.     It  is  one  of  the  poplars  {Popiiliis 
deltoides),  recognized  by  its  broadly  triangular  leaves  that  are 


Fig.  85, — Marram  grass,  Ammophila 
arenaria. 


THE  DUNES  AND  THEIR  PLANTS 


121 


borne  on  flattened  stalks.  The  buds  are  long,  tapering,  and 
curve  outward.  The  twigs  especially  on  young  trees  have  sharp 
ridges  running  down  the  bark  below  the  buds.  It  thrives  as  the 
sand  buries  it.  While  other  trees  sicken  and  die,  the  cottonwood 
literally  rises  to  the  emergency,  and  grows  so  as  to  keep  its  head 
above  the  accumulating  sand.  Moreover,  it  sends  out  roots  all 
the  way  up  and  down  its  buried  trunk  to  help  secure  needed 


.jj^^V^g^.f; 


"m. 


•\ 


^  7-  '^. 


Fig.  86. — Sand  cherry,  Prunus  pumila,  in  the  fore-dune  association 

moisture  for  its  vigorous  growth.  What  appear  like  low  cotton- 
woods  on  top  of  a  dune  are  really  the  topmost  branches  of  a 
tree  whose  original  roots  may  be  buried  a  hundred  feet  below 
the  rising  crest  of  the  dune.  Cottonwood  roots  run  out  many 
yards  through  the  sand  in  search  of  moisture. 

Miniature  dunes  may  be  built  up  around  clumps  of  bunch 
grass,  sand  cherry,  or  prostrate  juniper  (Fig.  69),  but  the  main- 
stay of  the  big  dune  is  the  bunch  of  cottonwoods  whose  seedlings 
caused  it  to  start,  and  that  have  grown  as  rapidly  as  the  dune 


122        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


has  increased  in  height.     There  are  many  other  plants  that 
assist    the    cottonwoods    to    stay    the    onward-moving    sands. 

Bunch  grasses  and  the  others  mentioned  above 
are  efficient  binders.  Their  intertangled  roots 
serve  to  enmesh  the  sand  and  prevent  its  being 
blown  away.  Sand  cherry,  the  smooth  and 
glandular  willows,  bittersweet,  horsetail,  are 
all  forms  that  can  stand  the  open  sand  areas 
along  with  the  cottonwood  and  when  once 
established  help  to  hold  the  shifting  sand.  So 
these 'form  a  part  of  the  cottonwood  association. 
To  say  that  these  plants  thrive  here  does  not 
mean  that  they  live  only  in  such  barren  places. 
The  cottonwood  grows  magnificently  on  rich 
Fig.  87.— The  soil;  but  here  on  the  sands  it  is  without  com- 
furry  willow,  Salix  petitors.  The  red-osier  dogwood  is  found 
^■^^  ^^^  ^'  growing  luxuriantly   on    the  margins  of    the 

swamps,  but  it  can  endure  the  dunes  and  keep  its  head  above 
even  rapidly  accumulating  sand  (Fig.  89). 


k:% 


■='"*in'  I  ifcii 


»^':sss?-5| 


j^>>*^t:^ig. 


Fig.  88. — The  cottonwood  zone  with  fore-dune  and  storm  beach  in  foreground 

The  efforts  of  the  plants  to  establish  themselves  and  trans- 
form the  shifting  sands  into  permanent  soil  would  be  in  vain 
were  it  not  for  the  fact  that  the  lake  is  constantly  piling  up  new 
dunes  in  front  of  those  already  formed.  These,  as  they  grow, 
cut  off  the  brunt  of  the  wind  from  those  in  the  rear  so  that  the 
conditions  of  life  are  less  severe  on  these  protected  dunes,  and 


THE  DUNES  AND  THEIR  PLANTS 


123 


vegetation  may   grow  more   luxuriantly.     By   the   time   that 
several  generations  of  cottonwoods,  together  with  many  more 


N^al^ 


,  '-> 


^ 


^^  ^ 


w 


Fig.  89. — Steep  side  of  a  dune  with  red-osier  dogwood,  Cornus  stolonijera, 
and  bunch  grass  serving  as  binders. 

of  the  shorter-lived  shrubs  and  the  associated  annuals,  have  lived 
and  died,  the  sand  has  become  so  altered  by  their  decomposed 


124        ^  NATURALIST  IN  THE  GREAT  LAKES  REGION 

remains  as  to  be  capable  of  holding  enough  moisture  to  support 
a  new  set  of  plants. 

Jack  pines,  then  white  pines,  and  a  whole  new  set  of  associated 
plants,  begin  to  change  the  appearance  of  the  dunes,  back  in  the 
pine  association  (Fig.  90).  The  arbor  vitae,  improperly  called 
the  white  cedar,  the  red  cedar,  the  common  juniper,  and  the 
prostrate  juniper,  are  conspicuous  and  give  a  northern  air 
to  these  dune  areas.     The  associated  plants  are  mostly  those 


Fig.  90. — At  the  edge  of  the  pine  association  looking  toward  the  cottonwooJ 
zone.  The  tall  trees  at  left  are  white  pines,  Piniis  strobus.  At  the  right  are 
red  cedars,  Junipcrus  virginiana,  with  little  bunches  of  spreading  juniper, 
Juniper  us  communis. 

usually  recognized  as  northerners.  The  bearberry  covers  the 
ground  with  its  glistening  leaves;  shinleaf,  checkerberry,  prince's 
pine,  star  flower,  and  false  lily-of-the- valley  are  common.  Blue- 
bells, puccoon,  horsemint,  hairy  phlox,  St.  Johin's-wort,  star  grass, 
Solomon's  seal — both  true  and  false — bellwort,  and  the  wild 
rose  make  these  dunes  gay  with  blossoms.  Staghorn  sumac, 
dwarf  sumac,  aromatic  sumac,  and  red-osier  dogw^ood  make 
dense  thickets  of  shrubs,  while  bittersweet,  woodbine,  poison 
ivy,  and  grape  add  to  their  impenetrability. 


THE  DUNES  AND  THEIR  PLANTS 


125 


Fig.  91. — The  bearberry,  Arctostaphylos  Uva-ursi:  above  habitat,  below  detail 


126      A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


95 


Figs.  92-100:  Fig,  92. — Spray  of  arbor  vitae,  Thuja  occidentalis;  Fig.  93. — 
Shinleaf ,  Fyrola  elliptica;  Fig.  94. — Checkerberry,  Gaullheria  procmnhens;  Fig.  95. — 
Prince's  pine,  Chimaphila  vnibellata;  Fig.  96. — Bluebell,  Campamda  rotundifolia; 
Fig.  97. — Puccoon,  Lithospermum  cancscens;  Fig.  98. — Horsemint,  Monarda 
punctata;  Fig.  99. — St.  John's-wort,  Hypericum  Kalmianum;  Fig.  100. — Bellwort, 
Uvular  ia  grandijiora. 


THE  DUNES  AND  THEIR  PLANTS 


127 


The  pines  among  the  evergreens  bear  their  needles  in  clusters, 
the  jack  pine  having  two  short  needles  in  each  group,  the  white 
pine  five  long  ones.  The  arbor  vitae  (Fig.  92)  has  scalelike, 
diminutive  leaves  that  overlap.  The  twig  is  flat  and  fanlike. 
The  red  cedar  is  a  juniper.  All  the  junipers  have  very  sharp 
needles,  rather  irregularly  borne  on  the  twig.  The  red  cedar 
(Fig.  90)  is  tall,  plumelike,  growing  to  be  a  good-sized  tree, 
though  usually  not  large  in  the  dunes.     The  needles  are  quite 


Fig.   ioi. — Star  flower,   Trientalis  americana  (center  foreground)  and  false 
lily-of-the-valley,  Maianthemum  canadense,  in  pine  zone  at  the  Dunes. 

small,  crowded  in  pairs,  each  one  opposite  its  mate.  The 
common  juniper  (Fig.  90)  is  a  spreading  shrub,  while  the 
prostrate  juniper  (Fig.  69)  lies  close  to  the  ground,  a  straggling 
shrub.  The  former  has  the  leaves  in  threes,  whorled  on  the 
stem,  the  latter  has  them  in  pairs  opposite  each  other.  The 
bearberry  or  kinnikinnick  (Fig.  91)  is  a  sprawling  shrub  that 
grows  often  in  great  masses.  The  oblong  leaves  are  leathery 
and  lustrous  green  the  year  round.  The  flowers  are  little  pink, 
pendant  urns,  the  fruit  a  red  berry  with  seeds  that  occupy  most 


128       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


of  it.     Shinleaf  (Fig.  93) ,  checkerberry  (Fig.  94) ,  and  prince's  pine 
(Fig.  95)  are  all  small,  low,  shrubby  plants  with  evergreen  leaves, 

belonging  to  the  heath  family. 
Shinleaf  has  rounded  leaves, 
and  its  flowers  are  borne  in  a 
loose  cluster  somewhat  like 
those  of  the  lily-of- the- valley. 
The  checkerberry  has  three  or 
four  glistening,  thick,  leathery 
leaves.  It  stands  only  two 
or  three  inches  high.  The 
flavor  of  the  leaves  is  that 
of  wintergreen  candy.  The 
Fig.  102.— Blue  star  grass, Si syrmchium    leaves  of  prince's  pine  are  long, 

angustifoUiim.  -       .i      i  J.^  ^ 

narrow,  toothed  on  the  edges, 
and  crowded  on  the  short  upright  stalks.  Star  flower  (Fig.  10 1) 
is  a  low^  plant  bearing  a  single,  delicate,  w^hite  blossom  above 
a  whorl  of  lance-shaped  leaves.     False  lily-of-the- valley  {Maian- 


FiG.  103. — False  Solomon's  seal,  Smilacina  racemosa 

themuni  canadense)  has  a  raceme  of  small  white  flowers  borne 
on  a  plant  with  two  or  three  parallel-veined,  thin  leaves. 
Bluebell   (Fig.  96)  has  linear  leaves  and  delicate  blue,  fairly 


THE  DUNES  AND  THEIR  PLANTS  129 

large,  bell-shaped  blossoms.  Puccoon  (Fig.  97)  is  a  low  hairy 
plant  with  clusters  of  brilliant  orange  blossoms.  Horsemint 
(Fig.  98)  is  an  annual  plant  with  strongly  serrated  leaves.  The 
yellow  flowers  are  not  large  but  are  subtended  by  conspicuous 
yellowish-purple  bracts  that  make  the  blossom  clusters  at  the 
ends  of  the  stalks  showy  affairs.  The  phlox  in  the  dunes  is  so 
like  the  garden  flower  of  the  same  name  it  will  be  promptly 
recognized.  There  are  three  species  here.  The  hairy  phlox  has 
a  hairy  stem  and  sharp,  pointed,  lance-shaped  or  linear  leaves. 
This  is  the  only  one  common  in  the  pine  association,  though  it  is 
also  found  still  farther  back.  The  St.  John's-wort  (Fig.  99)  has 
leaves  that  are  dotted  with  fine  translucent  spots.  The  flowers 
are  yellow  and  of  quite  good  size.  Star  grass  is  not  a  grass  really, 
though  its  leaves  are  long  and  narrow  like  those  of  grass.  The  star- 
shaped  flowers,  together  with  the  narrow  grasslike  leaves,  make 
it  easily  recognized.  Two  species  are  common :  one  bears  yellow 
flowers — the  yellow  star  grass — ^the  other,  blue  flowers — blue-eyed 
grass  (Fig.  102).  Solomon's  seal  receives  its  name  from  the  fact 
that  it  has  a  long  underground  stem  on  which  are  a  number  of 
circular  scars  like  seals,  each  being  impressed  at  the  point  where 
a  year's  growth  above  the  ground  was  attached.  The  leaves  of 
the  plant  are  broadly  lance-shaped  and  parallel-veined.  The 
flowers  are  borne  in  pairs  on  the  axils  of  the  upper  leaves  of  the 
pliant,  unbranched  stem.  False  Solomon's  seal  or  spikenard 
(Fig.  103)  is  quite  similar  but  a  somewhat  lustier  plant,  and  the 
blossoms  are  in  a  cluster  at  the  end  of  the  stem  instead  of  in 
the  axils  of  the  leaves.  Rosa  blanda  is  the  common  wild  rose  of 
the  dunes,  though  R.  Jiumilis  and  R.  acicularis  are  also  found 
frequently,  and  R.  Carolina  is  to  be  encountered  along  the  borders 
of  the  swales.  R.  blanda  is  low,  has  its  smaller  branches  free 
from  prickles,  and  its  flowers  are  usually  clustered.  Its  leaflets 
are  rounded  at  the  outer  end,  wedge  shaped  next  the  stem. 
R.  acicularis  is  wxll  armed ;  its  flowers  are  solitary  as  a  rule.  Its 
leaflets  are  obtuse  at  the  apex,  rounded  at  the  base.  R.  Jiumilis 
is  slender  stemmed,  armed  with  slender  prickles.     Its  leaflets  are 


I30       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

acute  at  both  ends.  The  bellwort  (Fig.  loo)  is  very  abundant 
in  spots  in  spring.  It  also  has  parallel-veined  leaves,  lance 
shaped,  borne  on  a  pliant,  unbranched,  low  stem.  The  flower 
is  single,  one  on  each  plant,  a  pendant,  yellow,  lily-like 
blossom. 

Staghorn  sumac  (Fig.  104)  is  a  shrub  readily  recognized  by 
its  coarse,  pithy  twigs  covered  with  velvety  hairs.  The  dwarf 
sumac  (Fig.  105)  is  a  small  edition  of  the  staghorn  with  this 
marked  difference,  that  in  the  latter  the  leafstalks  are  margined 
with  a  wing  between  the  leaflets  of  the  pinnately  compound 
leaves.  The  aromatic  sumac  (Fig.  106)  is  a  struggling,  low 
shrub  with  softly  hairy,  young  leaves.  The  leaves  have  three 
leaflets  and  have  a  pleasant  odor  when  crushed.  In  the  same 
genus  (Rhus)  of  innocent  plants  comes  the  poison  ivy  and  its 
even  more  poisonous  brother,  poison  sumac  (Fig.  107),  also 
called  poison  dogwood  or  poison  elder.  It  grows  in  the  swamps, 
not  on  the  dunes.  But  the  poison  ivy  (Fig.  1 13)  is  very  common 
in  the  dunes,  particularly  in  the  pine  association.  It  is  a  vine, 
though  often  appearing  as  a  shrub.  The  leaf  has  three  leaflets, 
as  has  that  of  the  poison  sumac,  and  like  the  latter  the  fruit  is 
white,  clustered,  appearing  berry -like.  Woodbine,  also  a  vine, 
drapes  itself  on  trees  and  shrubs  or  creeps  along  the  ground. 
Its  leaves  have  five  leaflets  growing  from  a  common  center. 
Bittersweet  (Fig.  108)  is  also  a  climbing  vine  with  glistening, 
green,  lance-shaped  leaves  and  a  red  fruit  in  autumn,  looking  like 
a  berry  in  the  center  of  four  yellowish  bracts  that  roll  back  to 
disclose  it.  Three  species  of  grapes — Vitis  cordifolia  (Fig.  109), 
the  frost  grape,  V.  aestivalis  (Fig.  no),  the  summer  grape,  and 
V.vulpinus  (Fig.  in),  the  river-bank  grape — are  found  in  the 
dunes — the  former  on  the  cottonwood  dunes,  the  latter  in  the 
pine  and  still  later  associations.  V.  vulpimis  is  most  likely 
to  be  found  on  the  margins  of  swales  and  swamps.  The  frost 
grape  has  small,  shiny,  black  berries;  the  summer  grape,  black 
berries  with  a  bloom;  the  river-bank  grape,  blue  berries  with  a 
bloom. 


THE  DUNES  AND  THEIR  PLANTS 


131 


108 


110' 


106 


109 


112 


Figs.  104-112:  Fig.  104. — Staghorn  sumac,  Rhus  typhina;  Fig.  105. — Dwarf 
sumac,  R.  copallina;  Fig.  106. — Aromatic  sumac,  R.  canadensis;  Fig.  107. — Poison 
sumac,  R.  Vernix;  Fig.  108. — Bittersweet,  Celastrus  scandens;  Fig.  109. — Frost 
grape,  Vitis  cordijolia;  Fig.  no. — Summer  grape,  V.  aestivalis;  Fig.  in. — 
River-bank  grape,  V.  vulpinus;  Fig.  112. — Sassafras,  Sassafras  variifolium. 


132 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Back  of  the  pine  association  comes  in  order  the  black  oak 
association.  No  single  association  of  the  dune  complex  is  more 
distinctive  than  this  association,  so  many  of  the  plants  are  pecul- 
iar to  it.  The  black  and  chestnut  oaks  are  the  common  large 
trees.  There  is  a  wealth  of  characteristic  small  trees  and  shrubs, 
sassafras,  shadbush,  pincherry,  chokecherry,  hop    tree,   dwarf 

blackberry,  known  by  its  stiff 
prickers,  huckleberry,  blueberry, 
bush  honeysuckle.  The  conspicu- 
ous herbaceous  flowering  plants  are 
equally  characteristic;  the  spider- 
wort,  bastard  toadflax,  anemone, 
columbine,  rock  cress,  lupine,  hoary 
pea,  bush  clover,  wild  geranium, 
milkwxed,  flowering  spurge,  bird's- 
foot,  and  arrow-leaved  violets, 
prickly-pear  cactus  (Fig.  60) ,  butter- 
fly wxed,  green  milkweed,  wild 
bergamot,  lousewort,  blazing  star 
(Fig.  134),  the  goldenrods,  the  sun- 
flowers, and  yellow  daisy. 

Sassafras  (Fig.   112)   is  readily 
known  by  its  green  twigs  with  the 
^  .        .        „,       sassafras   taste    and   its    mitten- 

FiG.     113. — roison    ivy,    Knits 

Toxicodendron;  a,  spray  showing    shaped  leaves.  Shadbush  (Fig.  114), 

aerial  rootlets  and  leaves;  b,  fruit    also  known  as  SUgar  plum,  service 

-both  one-fourth  natural  size   ^^^^i,   and  June  berry,  is  a  small 

{Farmers'  Bulletin  No.  86).  i      t   1  ■,       ^ 

tree  with  smooth,  light-gray  bark. 
The  leaves  of  the  species  in  the  dunes  are  thin,  and  the  edges 
finely  saw-toothed.  The  tree  bears  clusters  of  rather  large  white 
blossoms  in  the  spring  and  later  edible  fruits  that  turn  red  and  then 
purple  as  they  ripen.  Pin  and  chokecherries  are  known  by  their 
reddish  bark  that  peels  off  in  thin  layers  like  birch  bark,  though 
not  so  readily,  and  that  is  marked  by  conspicuous  horizontal 
lenticels.     Both  trees  have  the  blossoms  in  clusters.     In  the 


THE  DUNES  AND  THEIR  PLANTS 


114 


118 


ISO 


Figs,  i  14-122:  Fig.  114. — Shadbush,  Amelanchier  canadensis;  Fig.  115. — 
Pin  cherry,  Prunus  pennsylvanica;  Fig.  116. — Chokecherry,  P.  mrginiana;  Fig. 
117. — Hackleberry,  Gaylussacia  haccata;  Fig.  118. — Bush  honeysuckle,  Diervilla 
Lonicera;  Fig.  119. — Spiderwort,  Tradescantia  virginica;  Fig.  120. — Bastard  toad- 
flax, Comandra  nmhellata;  Fig.  121. — Anemone,  thimble  weed,  Anemone  cylin- 
drica;  Fig.  122. — Columbine,  Aquilcgia  canadensis. 


134       ^  NATURALIST  IN  THE  GREAT  LAKES  REGION 


former  (Fig.  115)  the  individual  flower  stalks  radiate  from  a 
common  point;  in  the  latter  (Fig.  116)  they  come  off  singly  from 
a  common,  main  stalk.  The  fruits  are,  of  course,  similarly 
clustered.  The  hop  tree,  really  a  shrub,  is  known  by  its  leaf 
made  of  three  leaflets  and  its  clustered  fruits,  achenes  with  wide, 
dry,  thin  borders,  looking  somewhat  like  dried  hops.  The  blue- 
berries and  huckleberries  (Fig.  117)  are  low  shrubs  with  rather 
thick,  leathery  leaves,  pink  bell-shaped  flowers  and  bluish  berries 
for  fruits.     In  the  autumn  their  leaves  turn  shades  of  dull  red  and 

give  a  brilliant  cast  to  great 
stretches  of  the  dunes  where 
they  are  abundant,  like  the 
autumn  colors  of  the  Scotch 
heathers.  These  plants  belong 
to  the  heath  family.  Bush 
honeysuckle  (Fig.  1 18)  is  a  low, 
opposite-leaved  shrub  with 
yellow  flowers  in  clusters  of 
three.  The  corolla  is  funnel- 
form,  the  flowers  conspicuous. 
As  they  age  they  turn  darker 
or  even  scarlet  to  crimson. 

Spiderwort  (Fig.  119)  is 
known  by  its  grasslike  leaves 
that  exude  a  mucilaginous  sap  when  broken.  Bastard  toadflax 
(Fig.  120)  is  a  low  plant  wdth  a  cluster  of  small  white  flowers. 
Anemone  cylindrica  (Fig.  121)  and  columbine  (Fig.  122)  are 
familiar  and  may  be  recognized  from  the  illustrations.  Rock 
cress  (Fig.  124)  is  one  of  the  mustard  family  with  small  white 
clustered  flowers,  each  with  four  petals.  The  lupine  (Fig.  123) 
has  palmately  compound  leaves  and  large  spikes  of  blue,  pealike 
flowers. 

The  hoary  pea  (Fig.  125)  or  wild  sweet  pea  is  an  erect, 
unbranched  plant,  a  foot  or  two  high,  with  typical,  clustered, 
pea-shaped  blossoms  that  are  yellowish  purple.     The  leaves  are 


Fig.  123. — Lupine,  Lupinus  perennis 


THE  DUNES  AND  THEIR  PLANTS 


135 


124 


25 


126 


127 


132 

Figs.  124-132:  Fig.  124. — 'Kook  crts?,,  Ar obis  lyrata;  Fig.  125. — Hoary  pea, 
Tephrosia  virginiana;  Fig.  126. — Bush  clov^er,  Lcspedeza  capilata;  Fig.  127. — 
Wild  geranium,  Geranium  carolinianum;  Fig.  128. — Flowering  spurge.  Euphorbia 
corollata;   Fig,  129. — Bird's-foot  violet,  Viola  pedata;   Fig.  130. — Butterfly  weed, 

Asdepias  tuhcrosa;    Fig.   131. — Arrow-leaved   violet,   Viola  sagitlata;   Fig.   132. — 
Lousewort,  Pedicularis  canadensis. 


136       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

compound  with  seven  to  twenty-five  leaflets.  The  roots  are 
fibrous  and  very  tough,  serving  wxU  for  string  on  emergency. 
Bush  clover  (Fig.  126)  is  a  tall  slender  plant  with  a  covering  of 
silky  hairs.  The  compound  leaves  consist  of  three  leaflets  which 
are  long  and  narrow.  The  round  heads  of  yellowish  blossoms  are 
sessile  in  the  axils  of  the  upper  leaves.  The  wdld  geranium  of 
the  black  oak  association  is  Geranium  carolinianum  (Fig.  127). 
The  leaf  is  shaped  much  like  that  of  the  sweet-scented,  deeply 


Fig.  133. — Wild  bergamot,  Monarda  fistulosa 

cut  leaf  of  the  common  garden  geranium.  The  flower  is  about 
one-half  inch  broad,  pale  purple,  and  the  seed  pod  bears  a  short 
beak.  Geranium  macidatum,  a  closely  related  species,  is  found 
farther  back  in  the  mixed  oak  association.  Flowering  spurge 
(Fig.  128)  has  an  erect  stem  with  narrow  leaves.  At  its  top  a 
cluster  of  stalks  arises  from  a  common  point  surrounded  by  a 
whorl  of  green  bracts.  These  stalks  branch  rapidly,  and  each 
branch  terminates  in  a  w^hite  blossom.  The  juice  of  the  plant 
is  milky.  Bird's-foot  and  arrow-leaved  violets  may  be  identified 
from  the  figures  of  the  plants  (Figs.  129,  131).     Butterfly  weed 


THE  DUNES  AND  THEIR  PLANTS 


137 


is  one  of  the  milkweeds,  although  it  does  not  have  a  milky  juice. 
The  clustered  blossoms  are  brilliant  orange  and  shaped  like 
those  of  the  common  field 
milkweed  (Fig.  130).  Wild 
bergamot  (Fig.  133)  has  a  char- 
acteristic odor.  The  corolla  is 
long,  violet  or  pink,  and  hairy 
in  the  throat.  The  blossoms 
are  clustered  and  the  cluster 
is  subtended  by  bracts,  the 
upper  ones  of  which  are  col- 
ored white  or  purplish.  Louse- 
wort  (Fig.  132)  is  a  low  hairy 
plant  with  pinnately  parted 
leaves  and  yellow  flowers 
crowded  by  a  spike  at  the  top 
of  the  stem.  The  blazing  stars 
(Fig.  134)  are  tall,  slender, 
unbranched  composite  plants 
with  small  narrow  leaves. 
They  are  so  slender  they  look 
like  fuzzy  green  stakes  set  in 
the  ground.  The  two  common 
species  in  the  black  oak  area 
are  Liatris  cylindrica  and  L. 
scariosa.  The  former  has  only 
a  few  heads  and  reddish- 
purple  flowers,  the  latter  many 
heads  on  the  stalk  and  these 
good  sized. 

The  mixed  oak  association 
(Fig.  135)  is  characterized  by 
black,  chestnut,  white,  and  red  oaks  (Fig.  136),  with  a  mixture 
of  slippery  or  red  elms  and  basswoods,  while  among  the  smaller 
trees  water  beech   and   hop   hornbeam   are  peculiar.     Yellow 


Fig.  134, — Blazing  star,  Liatris  spicala 


138        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

lady's-slipper,  hepatica,  ]\Iay  apple,  Geranium  mactdatum, 
Canada  violet,  the  long-spurred  violet,  and  rattlesnake  root  are 
characteristic  and  indicate  the  approach  of  the  climax  forest 
association  which  will  be  discussed  in  a  later  chapter. 

The  elms  are  known  by  their  vase  shape  and  by  the  fact  that 
the  buds  come  out  on  opposite  sides  of  the  twigs  so  that  the 
branch  with  its  twigs  is  always  flat,  spread  out  fanwise.     The 


Fig.  135. — ]\Iixed  oak-dune    area.     Note  large  white  oak,  Qiiercus  alba,  in 
center  of  picture;  near  it  are  red  oaks,  Q.  rubra. 

last  feature  is  also  common  to  the  basswood,  and  these  are  the 
only  trees  in  our  area  that  do  possess  this  character.  The  bass- 
wood  has  large  heart-shaped  leaves,  lopsided  at  the  base.  The 
bark  of  the  tree  is  smooth,  except  that  it  is  often  riddled  with  the 
holes  of  the  sapsucker  arranged  in  rows  around  the  trunk. 
Water  beech  (Fig.  137)  has  a  fluted  trunk  with  smooth  bark. 
Hop  hornbeam  has  a  finely  shredded  bark  that  pulls  off  in  long 
stringy  strips.  Both  these  trees  have  leaves  that  resemble  those 
of  the  elm. 


THE  DUNES  AND  THEIR  PLANTS 


139 


Fig.  136. — Leaves  and  acorns  of  the  oaks:  a,  red  oak  (Qucrcus  rubra);  b, 
pin  or  swamp  oak  (Q.  paluslris);  c,  northern  pin  oak  {Q.  ellipsoidal  is);  d,  scarlet  oak 
{Q.  coccinca);  c,  black  oak  {Q.  vclutina);  f,  white  oak  (Q.  alba);  g,  bur  oak 
{Q.  macrocarpa);  h,  blackjack  (Q.  marylandica);  i,  swamp  white  oak  {Q.  bicolor); 
j,  cinquapin  oak  (Q.  Milhlenbergii);  k,  shingle  oak  {Q.  imbricaria) ;  /,  basket  oak 
{Q.  Michauxii). 


I40       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


The  yellow  lady 's-slipper  or  moccasin  flower  can  be  recognized 
from  the  illustration,  for  it  is  so  unusual  a  blossom  (Fig.  138). 
Hepatica  or  liverwort  (Fig.  139)  has  a  three-lobed,  dark,  mottled 
leaf;  the  pale  pink  or  lavender  blossoms  come  early  in  the 
spring.  May  apple  (Fig.  140)  has  large  circular  leaves,  the  stem 
attached  at  the  center.  The  large  creamy  white  blossoms  spring 
from  the  fork  of  the  stem,  the  blossoming  plant  always  bear- 
ing two  leaves.     Geranium  maculaitwi  (Fig.  141)  is  similar  to 

G.  carolinianiim  of  the  black 
oak  association.  Its  leaf  is 
not  as  finely  cut,  having 
only  five  wedge-shaped  lobes. 
The  blossom  is  larger,  nearly 
an  inch  across,  and  is  light 
purple.  Canada  violet  (Fig. 
142)  has  a  branched,  leafy 
stem.  The  blossom  is  yellow 
tinged  with  violet  on  the  out- 
side, white  inside.  The  long- 
spurred  violet  (Fig.  143)  has 
so  conspicuously  long  a  spur 
that  it  is  not  to  be  mistaken 
for  any  other  in  the  Chicago 
region.  B oth  these  violets  are 
conspicuously  present  in  the 
climax  forest.  Rattlesnake 
root,  Prenanthes  alba,  is  a  composite  with  a  stout  and  fairly  high 
stem,  bearing  leaves  roughly  triangular,  though  very  variable  in 
form  and  lobing.  The  flowers  are  white,  a  dozen  or  so  in  a  head 
with  many  heads  in  a  cluster  (Fig.  144) .  The  summary  of  charac- 
teristic plants  is  given  in  the  tabulation  at  the  close  of  this  chapter. 
The  dune  complex  is  by  no  means  as  simple  as  the  foregoing 
discussion  would  seem  to  indicate,  for  there  are  additional 
physiographic  changes  that  are  constantly  going  on  that  inter- 
fere with  the  orderly  progression  sketched  above.     Whenever  a 


Fig.    137. — Trunk   of   water   beech, 
Carpinus  caroliniana. 


THE  DUNES  AND  THEIR  PLANTS 


141 


new  dune  forms  near 
the  shore  it  diverts 
the   strong  winds  in 
its  neighborhood,  for 
they   are  blocked  in 
certain  directions  and 
go  scurrying   around 
its  ends  to  blow  with 
great  vigor  upon  the 
older  dunes  from  new 
angles.     Not  infre- 
quently a  poorly  pro- 
tected portion  of  some 
old  dune  is  exposed 
thus  to  the  scouring 
action    of   the   sand- 
laden  blast,   and  its 
relatively   loose   soil 
begins  to  blow  away. 
What  was  an  estab- 
lished dune  may  be 
more  or   less   com- 
pletely blown    away 
(Fig.  14).    Such  blow- 
outs are  common, 
and  they,  of  course, 
set  back  an  area 
that   had   perhaps 
arrived    at  the 
black  oak  stage  to 
the  fore-dune  stage 
of  shifting  sands  in 
which  only  the  few 
hardy  annuals  can 
grow. 


Fig.  138. — Yellow  lady's-slipper,  Cypripcdimn  parvi- 
florum.  I.  Front  view  of  flower;  11,  III,  side  and  front 
view  of  stigma  and  pollinia.    Drawing  by  L.  N.  Johnson. 


142       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

Moreover,  such  blow-outs  uncover  whatever  the  advancing 
dune  buried.  Under  such  conditions  cottonwoods  show  their 
resiliency  by  sending  out  leafy  shoots  on  old  buried  trunks  that 


Figs.  139-144:  Fig.  139. — Hcpatica,  Hcpatica  triloba;  Fig.  140. — May  apple, 
Podophyllum  pdtatuni;  Fig.  141. — Wild  geranium,  Geranium  macidatum;  Fig. 
i42.-«-Canada  violet,  Viola  canadensis;  Fig.  143. — Long-spur  violet,  V.  rostrata; 
Fig.  144. — Rattlesnake  root,  Prenanthes  alba. 

bear  numerous  roots.  The  buried  pines,  killed  completely  by 
their  burial,  stand  out  as  giant  skeletons,  ghosts  of  their  former 
selves.  Such  resurrections  are  no  uncommon  sight  in  these 
forest  graveyards.     Sometimes  the  fall  of  a  great  tree  on  one 


THE  DUNES  AND  THEIR  PLANTS  T43 

of  the  older  dunes  may  expose  enough  of  the  loose  sandy  soil  to 
the  wind  to  initiate  a  blow-out. 

It  is  very  evident,  then,  that  any  given  area  in  the  dune 
region  must  be  interpreted  in  the  light  of  the  complex  of  forces 
operative  upon  it.  Frequently  one  will  get  into  a  region  that 
is  easily  recognized  as  a  cottonwood  dune,  a  black  oak  associa- 
tion, or  an  interdunal  swamp  area,  but  not  infrequently  a  par- 
ticular spot  will  be  in  transitional  conditions,  a  swamp  being 
invaded  by  a  moving  dune  perhaps,  where  within  a  rod  one  may 
pass  from  abundant  water  to  bone-dry  sand,  from  sphagnum 
and  pitcher  plants  and  a  crowded  vegetation  to  a  barren  sand 
slope.  Old  dunes  are  invaded  by  new  ones,  oaks  superseded  by 
cottonwoods.  In  fact,  the  zones  as  presented  above,  while  often 
regularly  placed,  are  at  times  mixed  in  a  thorough  jumble  as 
blow-outs  occur,  moving  dunes  blow  rapidly  inland,  or  as  the 
succession  is  here  or  there  retarded  or  accelerated  by  other  local 
conditions. 

The  following  table  presents  a  summary  of  the  plant  associa- 
tions in  the  Dunes.  It  shows  in  which  association  each  plant 
listed  is  most  likely  to  occur.  It  would  be  well  for  the  student 
to  make  a  similar  summary  for  each  of  the  succeeding  chapters 

•  •  •  •  •  • 

viu-xni. 


144 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Common  Name  of  Plant 


Trees,  deciduous 

Balsam  poplar 

Basswood 

Chokecherry 

Pincherry 

Cottonwood 

Elm,  American  white 

Elm,  red  or  slippery^ . 

Hop  hornbeam 

•June  berry 

Oak,  black 

Oak,  chestnut 

Oak,  red 

Oak,  white 

Sassafras 

Shadbush    {see  June 
berry) 

Poplar    (see    Balsam 
poplar) 

Water  beech 

Shrubs,  deciduous 

Bearberry 

Blueberry 

Blueberry, late 

Cherry,  sand 

Dogwood,  flowering . 

Dogwood,  panicled . . 

Dogwood,  red-osier. . 

Hackberry,  dwarf .  .  . 

Honeysuckle,  bush  . . 

Hop  tree 

Huckleberry 

New  Jersey,  tea 

Rose,  wild 

Rose,  wild 

Rose,  wild 

Sumac,  aromatic. .  .  . 

Sumac,  dwarf 

Sumac,  staghorn. .  .  . 

Viburnum,  maple- 
leaved  

Willow,  furry 

Willow,  prairie 

Willow,  smooth 

Witchhazel 


Scientific  Name 
t 


Poptdus  halsamifera . .  . . 

Tilia  amcricana 

Prunus  virginiana 

P.  pennsylvanica 

Populus  deltoides 

Ulmus  americana 

U.fidva 

Ostrya  virginiana 

Amelanchier  canadensis . 

Quercus  vclutina 

Q.  MUhlenhergii 

Q.  rubra 

Q.  alba 

Sassafras  variifolium . .  . 


Carpinus  caroliniana . 


o 


c 
■   "1 


Arctostaphylos  Uva-ursl. .  . 
Vaccinum  pennsylvanicum 

V .  vacillans 

Prunus  pumila 

Cornus  florida 

C.  paniculata 

C.  stolonifera 

Ccltis  occidentalis  pumila . 

Diervilla  Loniccra 

Plelca  trifoUata 

Gaylussacia  haccata 

Ccanothus  americanus .  .  .  . 

Rosa  acicularis 

R.  hlanda 

R.  humilis 

Rhus  canadensis 

R.  copallina 

R.  typhina 


Viburnum  acerifolium . 

Salix  syrticola , 

S.  humilis 

S.  glaucophylla 

HamameUs  virginiana . 


o 
o 

o  ^ 
^  IX 

o< 
U 


o 


a 
Si 


pq 


* 
* 


* 


* 
* 


* 
* 

* 

* 
* 
* 

* 


-a  o 


* 
* 
* 

* 
* 
* 
* 
* 


* 
* 


THE  DUNES  AND  THEIR  PLANTS 


145 


Corrimoa  Name  of  Plant 


Evergreen  trees  and 
shrubs 

Arbor  Vitae 

Cedar,  white  {see  Ar 
bor  Vitae) 

Cedar,  red 

Juniper,  common .  .  . 

Juniper,  prostrate . .  . 

Pine,  jack 

Pine,  white 

Vines 

Bittersweet 

Grape,  fox 

Grape,  summer 

Grape,  wild.  ....... 

Ivy,  poison 

Virginia  creeper 

Herbaceous  plants — 
flowering 

Arbutus 

Aster 

Aster 

Anemone 

Beach  pea 

Bean,  sand 

Bearberry 

Bedstraw 

Bellwort 

Bergamot,  wild 

Blazing  star 

Blazing  star 

Bluebell 

Broom  rape 

Bugseed 

Butterfly  weed 

Cactus  (see  Prickl}' 
Pear) 

Checkerberry 

Cherry 

Cherry,  ground 

Cinquefoil,  beach  .  .  . 

Cinquefoil,  shrubby . 

Cinquefoil,  silver  .  .  . 

Clover,  bush 

Co'^klebur 

Columbine 

Cranesbill  {see  Ge- 
ranium) 

Cress,  rock 


Scientific  Name 


Thuja  occidental  is 


Jtmiperus  virginiana . 
Juniperus  communis . 

J.  horizontalis 

Pinus  Banksiana  . . .  . 
P.  strobus 


Celastrus  scandens .  . 

Vilis  vulpina 

V .  aestivalis 

V.  cordifolia 

Rhus  Toxicodendron . 
Psedera  quinquefolia . 


Epigaea  re  pens 

Aster  linari  if  otitis 

A .  sericeus 

Anemone  cylindrica  .  .  . 
Lathyrus  maritimus . .  .  . 
Strophostyles  helvola  .  .  . 
Arctostaphylos  Uva-ursi 

Galium  Aparine 

Uvularia  grandi flora. .  .  . 

Monarda  fistulosa 

Liatris  cylindracea 

L.  scariosa 


o 


Campanula  rotmtdifolia . 
Orobanche  fasciculata . .  . 
Corispermum 

hyssopifolium 

Asclepias  tuber osa 


Gaidtheria  procumbens . 

P.  virginiana 

Phy sails  lanceolata . . . . 
Potentilla  canadensis .  . 

P.fruticosa 

P.  Anserina 

Lespedeza  capitata .  .  .  . 
Xanthium  canadense .  . 
Aquilegia  canadensis  . . 


Arabis  lyrata. 


* 
* 


-a 
o 
o 

c  o 


u 
o 


<u 
a 


* 
* 

* 
* 


* 


5 


* 
* 

* 
* 
* 


* 

* 


a 
O 


* 
* 


146       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Common  Name  of  Plant 

Scientific  Name 

0 

< 

ri 

0 

tin 

Cottonwood 
Assoc. 

J 
0 
tn 

< 
(U 
C 

Black  Oak 
Assoc. 

Dandelion,  dwarf 

Krigia  atnplexicaulis 

* 
* 
* 
* 

Dandelion,  dwarf .  . 

K.  virginica 

* 

Daisy,  yellow 

Evening  primrose .  .  . 
Evening  primrose. .  . 
Everlasting 

Rudbcckia  hirta 

Oenothera  biennis 

* 
* 

0.  rhombipetala 

A ntennaria  plontaginijolia 
Gerardia  pedicular ia 

* 
* 

* 
* 

Foxglove,  false    .  .  . 

Frostweed 

Ilelianthemum  canadense  . 

* 

Geranium 

Geranium  carolinianiim . .  . 

Geranium 

G.  maculatum 

* 

Ginseng,  dwarf 

Goldenrod 

Panax  trifoliimi 

* 

Solidago  nemoralis    .    . 

* 
* 

Goldenrod 

S.  racemosa 

Goldenrod      ...    . 

S.  rigida 

* 

* 

Goldenrod 

S.  speciosa 

* 

Grass,  blue  stem 

AndropoQ^on  scoparius .  .  .  . 

* 

Grass,  marram 

A  mniophila  arenaria 

* 
* 
* 

* 
* 
* 

Grass,  rve 

Elvmus  canadensis 

* 

Grass,  sand  reed 

Calamovilfa  lon'^ifolia.  .  .  . 

Grass,  switch .  . 

Paniciun  virgatuni 

* 
* 
* 
* 
* 

Grass,  triple  awned  . . 
Grass 

A  ristida  tuberculosa 

Festuca  octoflora 

Grass 

Koclaria  cristata 

Grass 

S  phcnobholis  obtusata 

Grass,  goose 

Grass,  star 

Potentiila  Anserina 

Hvpoxis  hirsuta 

* 

* 

* 

Hepatica 

Horsemint.  . 

Hepatica  triloba      .  .    . 

* 
* 
* 

* 

Alonarda  punctata 

* 

* 

Knot  weed,  small 

Polygonella  articulata 

* 

Lady's-slipper, 

yellow 

Lily-of-the- valley, 
false 

Cypripedium  parviflorum. . 

* 

M aianthcniutn  canadense 

■jf 

Eousewort 

Pedicularis  canadensis . . 

* 
* 
* 
* 

Lupine 

May  apple 

Milkweed,  green.  .  .  . 
Pea.  beach 

Liipinus  perennis 

Podophyllum  pcUatum  .... 

* 

Acerates  viridiilora 

* 
* 

* 

Lathyrus  maritimus 

Tephrosia  virginiana.  .  .  . 

* 

Pea.  hoarv 

* 

Phlox,  bifid 

Phlox  bifida 

Phlox,  blue  .... 

P.  divaricata 

* 

Phlox,  hairy 

Pigweed,  winged .... 

Prickly  pear 

Prince's  pine 

Puccoon 

P.  -bilosa 

* 

* 

* 

Cycloloma  airiplicifolium  . 
Opuntia  Rafinesquii 

* 

* 

* 

Chimaphila  umbellata  .... 

* 

* 

Lithos t>ermum  canescens. 

* 

Rose,  rock 

Hudsonia  tomentosa 

* 

Rattlesnake  root 

Prenanthes  alba 

* 

Russian  thistle 

Salsola  Kali  tenuifolia .... 

* 

* 

* 

Sarsaparilla 

Aralia  uudicaulis   . 

* 

THE  DUNES  AND  THEIR  PLANTS 


147 


Common  Name  of  Plant 

Scientific  Name 

6 

0 

< 

Fore-Dune 
*         Assoc. 

Cottonwood 
Assoc. 

< 

c 

"2° 

r=5 

Sea  rocket    

Cakile  edcntida 

Sedge 

Carex  eburnea 

* 

Sedge 

C.  Muhlenbcrgil 

* 
* 
* 
* 
* 
* 

Sedge 

Sedsre 

C.  pcmisvlvanica 

C.  nmbellata 

Sedsfe 

Cy  perns  jiliculmis 

Sedge    

C.  Schwelnitzii 

Shinleaf 

Fyrola  elliptica 

* 
* 
* 
* 
* 

Shinleaf 

P.  seciinda 

Solomon's  seal 

Polygonatum  commutatuni . 

* 
* 
* 
* 

* 

Solomon's  seal,  false. 

Sniilacina  tellata 

Solomon's  seal,  false . 

S.  raceniosa 

Spiderwort 

Spurge,  seaside .     ... 
Spurge,  flowering.  .  . 

St.  John's-wort 

Star  flower 

Tradescantia  virginiana .  .  . 
Euphorbia  polygonijolia. .  . 
E.  corollata 

* 

* 

* 

♦ 

* 
* 

Hypericum  Kalmianum  .  . 

* 

Trieutalis  americana 

Sunflower  .  . 

Heliauthns  divaricatus 

* 

Sunflower 

H.  occidentalis 

Thistle,  sand 

Cirsium  Pitcheri 

Linaria  canadensis 

* 

* 

* 

Toadflax 

* 
* 

Toadflax,  bastard 

Comandra  iipibcllata 

Twinflower 

Linnaea  horealis               .  . 

* 

Violet,  arrow-lea^'ed . 

Viola  sagiUata 

* 
* 
* 

Violet,  bird's-foot.  .  . 

»  V .  pedata 

Violet,  blue 

V .  cucnllata 

* 

Violet,  Canada 

V .  canadensis            ...    . 

* 

Violet,  long-spurred  . 

Wormwood 

Wormwood 

Spore  bearers 

Rattlesnake  fern .... 

V .  rostrata 

* 

Artemisia  canadensis 

A .  caudata 

Botrychinm  virginianum .  . 

* 
* 

* 
* 

* 
* 

* 

* 

* 

Bracken  fern 

Pteris  aauilina 

* 

Horsetail  fern 

Eqiiisetum  arvense 

E.  Jivemale                

* 
* 

Scouring  rush 

CHAPTER  VIII 


ANIMALS  OF  THE  DUNES 

ONATION  of  animal  forms  in  the  Dunes 
is  quite  as  evident  as  that  of  the  plants. 
This  is  to  be  expected  since  the  location 
of  the  animals  is  determined  in  large 
measure  by  their  food  plants  or  by  nest- 
ing sites  that  in  turn  are  determined  by 
the  plants.  Before  calling  attention  to 
some  of  the  characteristic  animals  of 
each  zone  we  may  give  a  striking  example  of  the  difference  in 
habitat  of  the  several  species  of  the  tiger  beetles  (Fig.  145). 
The  white  tiger  {Cicindela  lepida)  and  the  copper  tiger  (C.  cupras- 
cens)  are  abundant  in  summer  along  the  wet  shore  just  out 
of  reach  of  the  waves  where  they  are  busy  feeding  on  small 
insects  washed  up  from  the  lake  and  on  the  maggots  of  common 
flies  that  live  in  larger  dead  animals  that  are  deposited  by  the 
same  agency.  The  white  tiger  flies  back  to  the  higher  parts  of 
the  fore-dune  area  and  to  the  cottonwood  zone  to  rear  its  young; 
in  the  former  area  the  openings  of  its  burrows  are  character- 
istic though  not  numerous,  in  the  latter,  abundant.  Cicindela 
Jiirticollis  digs  its  straight,  cylindrical,  vertical  burrows  in  which 
the  young  are  found  in  the  moister  parts  of  the  fore-dune  area. 
This  species  is  found  foraging  very  commonly  in  the  cottonwood 
zone,  especially  on  the  landward  side  of  the  dunes  that  border 
ponds  or  swales.  In  the  transition  belt  between  cottonwood  and 
pine  associations  occur  the  crooked  holes  of  the  young  and  the 
adults  of  the  large  tiger,  C.  fonnosa  generosa.  The  bronze  tiger 
(C  sciUellaris  lecontei)  is  characteristic  of  the  pine  association 
itself  where  it  rears  its  young,  and  is  found  also  in  the  adjacent 
black  oak  areas,  especially  in  bare  sandy  spots.     Finally,  as  one 

148 


ANIMALS  OF  THE  DUNES 


149 


travels  still  farther  back  from  the  lake  into  the  oak-hickory 
association  he  encounters  the  green  tiger  (C.  sexguttata) ,  though 
it  is  much  more  common  still  farther  back  in  the  hickory -maple 
and  maple-beech  forests.  Yet  other  species  are  confined  to  the 
borders  of  the  interdunal  ponds  (C.  tranqueharica)  to  the  margins 
of  sphagnum  bogs  (C.  ancocisconensis)  and  to  the  shores  of  small 
lakes  (C.  re  panda).  It  is  remarkable  that  species  so  closely 
related  should  occupy  such  closely  adjacent  areas  and  each  keep 


Fig.  145. — Species  of  tiger  beetles.  At  left,  Cicitidela  formosa  generosa. 
a,  Wing  cover  of  C.  lepida;  b,  C.  cuprascens;  c,  C.  hirticollis;  d,  C.  scutellaris  lecontei; 
e,  C.  sexguttata;  f,  C.  repanda;  g,  C.  anco'cisconensis;  h,  C.  limbalis.     All  X2. 


quite  strictly  to  its  own  narrow  belt.  Yet  such  is  found  to  be 
the  case  the  world  over;  closely  related  species  are  seldom  found 
living  together,  but  if  in  the  same  region  each  occupies  its  own 
restricted  area. 

These  tiger  beetles  are  all  predatory,  feeding  on  flies  and 
other  insects  which  they  often  capture  on  the  wing.  They  occur 
usually  on  bare,  sunny  spots.  Thus,  the  green  tiger  of  the  maple- 
beech  forest  is  found  on  the  open  paths.  They  are  wary  animals, 
rising  in  quick  flight  as  you  approach  and  flying  in  straight  lines 
some  distance  ahead  of  you  when  they  turn  as  they  alight  to 


I50       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

face  the  intruder.  The  larva  lives  in  a  burrow  in  which  it  is 
supported  at  the  top  by  a  spiny  hump;  the  huge  jaws  fill  the 
orifice  ready  to  seize  any  insect  that  unwarily  steps  on  the  living 
trap.  The  jaws  are  approximately  ground  color  so  that  you  are 
sometimes  aware  of  the  presence  of  the  burrows  when  what  was 
at  first  solid  ground  becomes  porous  as  the  numerous  larvae  drop 
back  into  their  holes  on  your  alarming  approach. 

That  the  dune  area  is  prolific  in  animal  life  may  be  realized 
from  the  result  of  an  animal  census  taken  in  midsummer  by 
Miss  Nell  Saunders,  whereby  she  found  in  a  mixed  area  of  swale, 
cottonwoods,  and  oaks  sixteen  million  animals  to  the  acre.  This 
population  was  distributed  as  follows:  three-quarters  of  a  million 
on  the  ground  stratum,  three  million  on  the  herbaceous  plants, 
ten  million  on  the  shrubs,  and  the  remainder  on  the  trees.  It  is 
evident  from  this  and  from  the  descriptions  to  follow  that  there 
is  a  vertical  zonation  of  life  as  well  as  a  horizontal  one. 

The  succeeding  societies  of  animals  beginning  with  those  near- 
est the  shore  are,  in  the  Dunes,  as  follows:  (i)  The  predatory 
ground  beetle  association  corresponding  to  the  beach  association 
of  the  plants.  (2)  The  digger  wasp  association,  corresponding  to 
the  fore-dune  and  cottonwood  zones.  (3)  The  bronze  tiger  asso- 
ciation corresponding  to  the  transition  zone  between  the  cotton- 
wood  and  pine  areas  and  the  pine  association.  (4)  The  ant-lion 
association,  equivalent  to  the  black  oak  plant  association.  (5) 
The  hylodes  association,  corresponding  to  the  mixed  oak  plant 
zone. 

While  both  the  wet  beach  and  the  storm  beach  (Fig.  8^)  are 
practically  free  from  plants,  they  are  inhabited  by  characteristic 
animals.  When  a  strong  offshore  wind  is  blowing,  hundreds  of 
species  of  insects  and  many  birds  from  the  territory  adjacent  to 
the  lake  blow  out  over  the  water  during  their  incautious  flights 
and  drop  exhausted  to  its  surface.  When  the  wind  shifts,  as  it  does 
almost  daily,  the  onshore  wind  piles  these  animals,  together  with 
dead  fish,  in  long  windrows  on  the  beach.  Some  of  the  insects 
survive  their  prolonged  immersion  and  crawl  under  stones,  chips, 


ANIMALS  OF  THE  DUNES  151 

and  bits  of  drift  on  the  storm  beach.  After  a  storm  one  may  pick 
up  hundreds  of  species  along  shore,  some  of  them  from  regions 
far  inland. 

Flesh  flies  and  carrion  beetles  are  to  be  found  feeding  on  and 
depositing  their  eggs  in  the  carcasses  of  fish  and  other  dead 
animals.  Digger  wasps  and  robber  flies  are  attracted  here  by 
the  numerous  insects  that  are  crawling  half-dead  from  the  water. 
Crows  and  herring  gulls  are  also  drawn  by  the  carrion,  the  latter 
are  present  in  great  flocks  in  the  fall,  fishing  offshore  as  well  as 
feeding  along  the  beach.  There  are  many  long-legged  shore 
birds  that  feed  on  these  insects  and  on  the  crustaceans,  wading 
out  in  the  shallow  water  to  hunt  them  or  running  along  the 
wet  sand.  The  least  and  semipalmated  sandpipers  are  fairly 
common.  In  spring  and  fall,  particularly  the  latter,  the  beach 
is  alive  with  knots,  sanderlings,  and  turnstones;  godwits,  cur- 
lews, and  willets  are  also  often  to  be  noted,  while  the  piping 
plover  is  not  only  found  frequently  here  but  occasionally  nests 
in  the  same  area.  The  Hudsonian  curlew,  the  willet,  and  the 
Hudsonian  godwit,  the  latter,  especially,  becoming  rare,  are  all 
birds  of  good  size  (15  to  17  inches  long)  with  slender  bills  over 
2  inches  long.  That  of  the  curlew  turns  down  distinctly,  a 
distinguishing  feature.  The  under  parts  of  the  willet  are  white, 
those  of  the  godwit,  chestnut.  Knot,  sanderling,  semipalmated 
and  least  sandpipers  also  have  long  bills  to  use  as  probes.  The 
birds  are  smaller,  however,  loj,  8,  6 J,  and  6  inches  long 
respectively.  All  are  mottled  black  and  gray  or  buff  abov^e. 
The  sanderling  has  three  toes  and  wing  bars;  the  others,  four 
toes  and  no  wing  bars.  The  small  size  of  the  last  two  serves  to 
make  their  recognition  certain.  The  breast  of  the  semipal- 
mated is  faintly  streaked  or  spotted  with  black;  that  of  the 
least,  heavily  streaked  or  spotted  with  brown.  The  turnstone, 
which  is  some  9I  inches  long,  has  a  back  strikingly  mottled  in 
black,  brown,  and  white  and  a  white  patch  at  the  base  of  the 
tail.  The  piping  plover  is  small  (7  inches),  very  pale  colored, 
almost  ghostlike  in  its  invisibility.     The  upper  parts  are  ashy; 


152        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


the  under  parts,  white.     There  is  a  black  bar  on  each   side 
of  the  breast,  the  two  sometimes  uniting  to  form  a  band  across 

the  breast. 

The  killdee  and 
semipahnated  plovers 
are  also  found  on  the 
beach,  though  more 
characteristic  of  pas- 
tures and  marshy 
uplands  respectively. 
The  former  is  about 
the  size  of  a  robin. 
It  has  two  black  bands 
crossing  its  front.  It 
repeatedly  whistles 
"killdee"  when  dis- 
turbed. The  latter  is 
smaller  (6j  inches)  and 

F1G.146.— Termites  or  white  ants,  rfrwe5^a2;z>a;  has  only  one  black 
fl,  Female;  6,  Male;  c,  Worker;  rf,  Soldier.  From  BiilL  band  across  its  front. 
Bureau  of  Entomology,  U.S.  Dept.  of  Agriculture.         rpj^^    spotted     sand- 

piper  is  also  common,  though  more  characteristic  of  the  shores 
of  streams  and  smaller  inland  lakes.  It  is  7I  inches  long, 
streaked,  barred,  and  spotted  all  over,  the 
under  parts  strongly  spotted  with  black 
on  a  white  ground.  It  bows  and  teeters 
as  it  comes  to  a  stand. 

Under  the  driftwood  of  the  storm  beach 
one  will  find  hiding  by  day  the  common 
toad,  many  predatory  beetles,   an    occa- 
sional mole  or  mouse,  all-night   prowlers        fig.  147.— The  sand- 
that  come  out  in  the  dusk   to   feed.     Here     colored  spider,  Trochosa 

too  one  finds  the  white  ants  or  termites    "^^^'''^^• 

(Fig.  146).    The  sand-colored  spider,  Trochosa  chierea  (Fig.  147), 

hunts  over  this  territory  to  good  purpose  by  day. 


ANIMALS  OF  THE  DUNES 


^53 


It  is  difficult  to  pick  out  from  such  a  miscellaneous  assemblage 
any  particular  form  by  which  to  name  the  association.  Perhaps 
it  may  be  called  the  predatory  ground  beetle  association  quite 
justly.  Such  beetles, 
including  the  white 
and  copper  tigers,  the 
searcher,  a  good-sized, 
bright,  bronze-green 
beetle;  the  fiery 
hunter,  a  black  beetle 
with  coppery  pits  on 
the  elytra  (Fig.  148); 
the  yellow-legs,  Galer- 
ites  j  anus  J    a    black 

beetle    with    legs    and  Fig.  148. — The  searcher,  Calosoma  scrutator,  and 

thorax  reddish  brown,    ^^'^  ^^'^  ^^^^^^'  ^'  '''^^^''"'^ 

and  others  are  always  present,  though,  in  many  cases,  they  are 

likely  blown  here  from  their  native  haunts  farther  inland.     At 


Fig.  149. — Holes  of  digger  wasp,  Microbembex  monodonta,  at  left;   wasp  at 
entrance  to  hole  at  right. 

any  rate  they  are  representative  of  the  whole  group  of  insect- 
eating  animals  so  characteristic  of  the  zone. 

The  fore-dune  zone  is  intensely  hot  in  summer.     The  sand 
burns  your  bare  feet  so  that  it  is  quite  unendurable.     Here 


154       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


many  inhabitants  dig  in  to  get  down  to  the  moist,  cool  sand  a 
few  inches  below  the  surface.  The  burrowing  spider  does  this, 
coming  out  at  dusk  to  hunt.  Its  holes  are  one-eighth  to  one-haK 
inch  in  diameter  and  5  or  6  to  20  inches  deep.  The  hole  is  sur- 
rounded in  early  morning  by  moist 
dabs  of  sand  thrown  out  in  excava- 
tion. The  full-grown  spider,  legs 
extended,  nearly  covers  the  palm  of 
your  hand.  It  is  colored  like  the 
sand.  Here  also  the  black  digger 
wasp,  Anoplius  diversus,  makes  its 
Fig.  150.— The  bee  fly,  Exoprospa.  holes  in  which  to  rear  its  young  and 

After  Willi ston.  ,      i       ,i  ..t-        'j         r        r       1 

stocks  them  with  spiders  for  food 
for  the  larvae.  The  holes  are  shallow  and  the  heat  serves  to 
incubate  the  eggs.  Two  other  digger  wasps  of  a  smaller  sort, 
Microhemhex  monodonta  (Fig.  149)  and  M.  spinulosa  (Fig.  67), 
or  Bembex  spinolae,  excavate  holes  that  are  so 
abundant  in  spots  the  surface  layer  is  per- 
forated like  a  sieve.  They  are  the  most  strik- 
ingly characteristic  features  of  this  area  and  it 
may  properly  be  designated  the  digger  wasp 
association.  Not  that  the  digger  wasps  are 
not  elsewhere  found.  But  they  are  nowhere 
else  so  conspicuous  and  dominating  a  part  of 
the  animal  consocies.  Bee  flies  (Fig.  150) 
hover  over  the  groups  of  wasp  holes,  dipping 
down  to  the  surface  every  once  in  a  while  to  ^^^  ^  —The 
deposit  eggs  at  the  entrance  of  some  wasp  hole  Willow-leaf  beetle, 
so  that  w^hen  the  latter  drags  in  flies  to  stock  Disonycha  qidnqnevit- 
her  nest  the  bee  fly  egg  may  be  carried  in,  too.  "  ^' 
The  bee  fly  larvae  live  parasitically  on  the  larvae  of  the  digger 
wasps. 

The  low  plants  of  the  fore-dunes,  sand  reed,  marram  grass, 
sand  cherry,  smooth  and  glandular  willows,  etc.,  are  relatively 
free  from  insect  pests.     Apparently  the  conditions  under  which 


ANIMALS  OF  THE  DUNES 


155 


they  live  are  too  severe  for  any  but  the  hardiest  of  their  enemies. 
The  willows  are  quite  free  from  the  willow  cone  gall.  One  leaf- 
eating  beetle,  Disonycha  qiiinquevittata  (Fig.  151),  is  common  on 
them.  It  is  about  one-third  inch 
long,  yellow  with  black  stripes. 
There  are  some  aphids  on  the  cher- 
ries but  the  ladybird  beetles  and 
syrphus  flies  keep  them  well  in  check. 
Several  snout  beetles  of  the  genus 
Sphenophorus  (Fig.  152)  are  very 
common  on  the  grasses.  The  larvae 
feed  on  the  roots  of  the  bunch  grass 
and  on  the  roots  of  sedges  in  nearby  swales.  Gnats  and  flies  that 
apparently  breed  down  at  the  shore  lodge  on  these  grasses  in  large 


Fig. 

Sphenophorus 


beetle, 


Fig.  153. — Nest  holes  of  bank  swallows 

numbers.  One  of  the  flies  has  a  vigorous  bite.  The  tor- 
mented camper  in  this  region  may  derive  some  satisfaction 
from  watching  the  swift  darting  flight  of  several  species  of 
dragon  flies  that  hunt  over  and  among  the  clumps  of  grass 
and  devour  many  of  these  flies  and  gnats.  (See  next 
chapter.) 


156       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Fig.  154. — ]\Iaritime  locust, 
Trhnerotropis  maritima. 


In  the  plant  associations  there  is  a  sharp  demarcation  between 
the  fore-dune  and  the  cottonwood  zone  that  comes  next,  for  the 
cottonwoods  add  a  strikingly  new  feature.  There  is  no  such 
separation  in  the  animal  associations,  and  both  fore-dune  and 
cottonwood  areas  may  be  included   in  the  one  digger  w^asp 

association.  True,  certain  new 
animals  appear.  The  kingbird  finds 
the  tops  of  the  cottonwoods  excellent 
lookouts  from  which  to  spy  the  in- 
sects upon  which  he  feeds.  But  he  is 
more  common  and  more  character- 
istic in  other  situations  as,  for  instance,  along  the  borders 
of  the  woods.  The  tree  swallow  nests  in  the  hollow  stumps 
of  old  pines  and  cottonwoods.  Their  backs  are  iridescent 
blue  green;  their  throats,  breasts,  and  bellies,  pure  white. 
Bank  swallows  nest  in  the  steep  sides  of  dunes,  especially 
where  blow-outs  make  sand  cliffs 
(Fig.  1 53) .  The  cottonwood  is  rela- 
tively free  from  the  insect  pests  that 
usually  accompany  it.  The  cock's 
comb  gall  is  not  frequent  on  it  here. 
Such  a  characteristic  woodborer  of 
the  cottonwood  as  Plectrodera  scal- 
ator  is  rare.  In  the  spring  when  the 
tree  is  in  blossom  certain  flies  and  beetles  are  attracted  by  its 
abundant  pollen,  but  these  are  also  common  on  the  willows  of 
the  fore-dune.  The  white  or  maritime  and  long-horned  locusts 
are  frequently  found  in  the  digger  wasp  zone,  though  they  are 
alsQ  found  in  the  bronze  tiger  zone. 

The  female  of  the  maritime  locust  (Fig.  154)  is  about  1.2 
inches  long;  the  male,  about  .  8  of  an  inch.  The  animal  is  light 
gray  to  reddish  brown  in  color,  the  under  side  almost  white.  It 
is  so  near  the  color  of  the  sand  as  to  be  nearly  invisible  until  it 
flies.  The  inner  wings  have  a  dark  band  along  the  margin  but 
a  transparent  tip.     The  inner  face  of  the  hind  femur  bears  three 


Fig.  155. — ^lottled  sand  locust, 

Sparagemon  wyomingianiim. 


ANIMALS  OF  THE  DUNES 


^S1 


black  bands.  The  long-horned  locust  (Fig.  156)  is  small,  the 
male  two-thirds  of  an  inch  long,  the  female  seven-eighths  inch. 
The  antennae  are  half  as  long  as  the  body,  or  more.  The  inner 
wing  has  the  basal  third  red,  orange,  or  rarely  yellow.  The 
middle  third  of  the  wing  is  covered  by  a  curved  black  band,  the 
outer  third  is  clear,  except  for  a  dusky  tip. 

Back  of  the  digger  wasp  association  comes  the  transition 
stage  and  the  pine  association  in  the  plant  zonation.     Both  of 


Figs.  156-159:  Fig.  156. — Long-horned  locust,  Psimdia  fcncsl rails.  After 
Lugger;  Fig.  157. — Lesser  migratory  locust,  Mdanoplns  atlanls.  After  Lugger; 
Fig.  158. — End  of  abdomen  of  male  of  narrow- winged  locust,  Melanoplus  angustl- 
pennls;  Fig.  159. — Sand  locust,  AgcneotcUlx  arenosus. 

these  support  nearly  the  same  animal  population,  and  it  is  a 
very  characteristic  one.  Nowhere  else  in  the  Chicago  area, 
unless  it  be  in  the  sphagnum-tamarack  swamps,  does  one  seem 
to  be  so  far  removed  from  the  expected  environment.  The 
coniferous  trees,  the  evergreen  shrubs,  and  the  herbaceous 
flowering  plants,  many  of  which  are  quite  boreal,  are  more 
striking  but  no  more  peculiar  than  the  animals  encountered. 


158       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


As  already  noted,  the  bronze  tiger  beetle  (Fig.  145)  is  here  as 

well  as  the  burrows  of  its  young.     Shelford  names  the  whole 

association  from  this  form,  although  the  adult  animal  is  found 

quite  as  commonly  back  in  the  next  association.     Here,  too, 

particularly  in  the  transition  area,  is  the 
large  tiger  beetle  (Fig.  145).  The  white  ant 
is  abundant  under  the  logs.  Digger  wasps 
are  still  in  evidence,  though  of  species 
different  from  those  of  the  preceding  zone. 
The  black  ant,  Lasius  niger  americanns, 
builds  its  nests  in  the  sand.  The  mottled 
sand  locust,  the  migratory  locust,  the 
narrow-winged  locust,  and  the  sand  locust 
are  pretty  well  confined  to  this  zone.  The 
Fig.  160.— Longhorn  mottled  sand  locust  (Fig.  155)  is  small,  the 

beetle,  Monohamfnus   female  being  about  I  inch  long,  the  male 

.8  of  an  mch.      Ihe  inner  wings  are  yellow 

with  a  dark,  curved  median  band.     The  antennae  are  as  long 

as  the  hind  femur.    The  tibia  is  coral  red  with  white  rings.    The 

lesser  migratory  locust  (Fig.  157)  is  also  small,  about  the  same 

size  as  the  preceding.     The  femur  of  the  hind 

leg  is  reddish  yellow  and  bears  two  oblique 

dark  bars  across  the  upper  outer  face.     The 

knees  are  black.     The  lower  part  of  the  face  is 

usually  pink.     The  inner  wings  are  thin  and 

colorless.    The  narrow- winged  locust  (Fig.  i  ^S) 

is  also  small,  slightly  under  an  inch.     The 

antennae  are  shorter  than  the  femur  of  the 

hind  leg.     The  hind  tibia  is  pale  blue  or  bright 

red.     The  inner  wings  are  transparent    and 

colorless.     The    sand    locust    (Fig.     159)    is 

small,  the  male  being  .6  of  an  inch  long,  the 

female  .8  inch.     The  animal  is  dull  brown,  the  hind  tibia  is  bright 

scarlet  with  a  basal  white  ring.     On  the  juniper  several  spiders 

are  found,  Philodromns  alaskensis,  Xysticus  formosus,  Dendry- 


FiG.  161. — Metallic 
wood-boring  beetle, 
Chalcophora  liber ta. 


ANIMALS  OF  THE  DUNES 


159 


phantes  octavus,  Theridimn  spirale,  all  small  and  fairly  widely 
distributed,  except  the  first. 

The  tree  stratum  is  the  one  on  which  the  largest  number  of 
conspicuous  and  characteristic  forms  are  found.  The  pitch 
moth  feeds  on  the  new  pine  shoots,  covering  itself  in  a  case  of 
pitch  and  excreta.  Longhorn  and  metallic  wood  borers  are  to 
be  encountered  under 
the  bark,  or  in  their 
tunnels  in  the  wood 
of  the  partially  dead 
or  wholly  dead  pines 
(Figs.  160  and  161). 
Here,  too,  one  finds 
certain  birds  and 
mammals  that  are 
more  or  less  confined 
to  the  pines.  Downy 
and  hairy  wood- 
peckers nest  here. 
The  golden-crowned 
and  ruby-crowned 
kinglets,  the  black- 
throated  green  war- 
bler, and  the  pine 
warbler  are  abundant 
during  migration. 


Fig.  162. — Chipmunk,  Tamias  striatiis  griseus 


The  black-capped  chickadee  is  nearly  always  present,  repeatedly 
calling  his  own  name.  The  ruffed  grouse  is  fairly  frequent  and 
nests  here  occasionally  or  in  the  adjacent  black  oaks.  The  red 
squirrel  that  is  so  constant  a  feature  of  the  coniferous  forests 
farther  north  is  frequently  encountered,  as  is  also  the  chip- 
munk (Fig.  162). 

When  the  stage  is  set  with  the  plants  of  the  black  oak  associa- 
tion the  animal  dramatis  personae  change  with  the  changing 
scenery.     This  has  been  designated   the   ant-lion   association. 


i6o       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


,  ■'* 


«^ 


The  conical  holes  of  the  young  are  conspicuous  in  spots  (Fig. 
163),  though  you  may  travel  over  these  black  oak  dunes  for  a 
long  time  without  encountering  them.  Still  they  are  confined 
to  the  black  oak  region.  The  pit  is  2  inches  or  so  in  diameter 
and  is  a  crater-like  depression  in  the  loose  sand.     At  the  bottom 

under  the  sand  lies   the  larva,  an 
ugly  little  duckling.     When  an  ant 
or  other  small  insect  goes  on  a  jour- 
ney it  may  step  over  the  edge  of 
such  a  depression,  slide  down  with 
the  caving  sand  in  spite  of  its  best 
efforts  to  escape,  and  be  seized  by 
the  jaws  of  the  waiting  larva.     A 
grass  blade  stuck   down    into    the 
sand  at  the  bottom  of  the  pit  will 
sometimes  bring  up 
the  larva  that  fastens 
its  jaws  into   it   and 
will  not  let  go  even 
when  pulled  out  of  its 
lair.    One  may  go  fish- 
ing for  the  tiger  beetle 
larvae   in  the   same 
way   with    occasional 
success.    The  ant-lion 

itself  is  a  gauzy 
Fig.  i63.-Ant-lion,  Myrmdion,  above  (after  ^^.'^^  ^^  creature  with 
Shelford)  and  holes  of  its  larvae.  i  i      i 

long  body  that  re- 
minds you  somewhat  of  a  very  lazy  damsel  fly.  Digger  wasps  are 
again  present,  particularly  a  big  black  and  orange  one  (.4  mmophila 
procera) .  A  curious  assemblage  of  southwestern  desert  forms  are 
found  here  on  the  ground  stratum.  The  cactus  (Fig.  60)  is  a  strik- 
ing plant,  particularly  if  you  inadvertently  sit  down  on  a  patch. 
The  sLx-lined  lizard  (Fig.  61)  is  common  in  the  same  locaUty, 
and  an  occasional  parokeet  is  seen  on  the  trees  or  shrubs  (rare). 


ANIMALS  OF  THE  DUNES 


i6i 


Certain  beetles  go  along  with  the  cactus  and  are  found  beneath 
its  leaves,  Lacon  rectangularis  (Fig.  164),  Prasocuris  phellandrus 
(Fig.  165).  All  these  forms 
even  invade  the  preceding 
pine  or  bronze  beetle  asso- 
ciation, and  to  find  the 
boreal  evergreens  and 
attendant  northern  ani- 
mals in  close  juxtaposition 
to  cactus  and  lizard  makes 
an  unwonted  contrast. 
The  six-lined  lizard  lays 
its  eggs  in  the  bronze  tiger 
zone,  as  does  also  the  blue  Figs.  164-165:  Fig.  164.— A  click  beetle, 
racer  (Fio"  166)  but  I  have  Lacon  rectangularis,  found  beneath  cactus; 
r  T     ,1  .        1      ji  Fisf.    16 V — A  leaf-eating  beetle,   Prasocuris 

found   the  animals  them-    ^,  ,,     ,  u  kv  ^-     -d  ^-u  s^ 

phellandrus,  same  habitat.     Both  X5. 

selves  more  common  in  the 

ant-lion  association.     Another  snake,  the  hognose  or  puff  adder 


Fig.  166. — Blue  racer,  Coluber  constrictor 

(Fig.  167),  is  fairly  common  in  this  ant-lion  association.  It  is  a 
mottled  animal,  a  foot  or  more  in  length,  that  spreads  and 
flattens  its  head  into  a  broad  triangle  after  the  manner  of  the 


1 62       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


poisonous  snakes  when  disturbed,  though  it  is  quite  harmless. 
If  teased  it  ''throws  a  fit"  and  Hes  semi-rigid,  belly  up,  apparently 
feigning  death. 

Half  a  dozen  new  orthoptera  are  found  on  the  ground  or 
shrubs  in  this  association:  the  rusty,  leather-colored,  sprinkled, 
and  coral-winged  locusts,  the  straight-lance  and  sword-bearing 
grasshoppers,  the  Texan  and  the  forked-tail  katydids.  The 
latter  two,  however,  have    a  very  wide  distribution  and  are 

not  therefore  at  all 
distinctive  of  this 
region.  The  rusty 
locust  is  from  .2-.6 
inches  long.  It  is 
russet  brown  in  color 
with  a  yellow  stripe 
down  the  back.  It 
has  a  bulky  body. 
Its  face  is  vertical. 
The  inner  wdngs  are 
transparent,  the  tip 
being  slightly  red. 
The  leather-colored 
locust,  a  closely  allied 
species,  is  often  found 
associated  with  it, 
especially  near  the  margins  of  the  swales,  where  the  latter  is  often 
found  on  the  coarse  grasses.  The  rusty  locust  is  stouter  than  the 
leather-colored,  and  its  antennae  do  not  exceed  .6  of  an  inch,  while 
in  the  leather-colored  they  do,  slightly.  The  sprinkled  locust 
(Fig.  1 68)  is  light  brown  (male)  or  clay  yellow  to  dark  brown 
(female) .  The  sides  of  the  shieldlike  covering  of  the  front  part  of 
the  thorax  bears  a  glistening  black  bar  in  the  male,  a  sprinkling  of 
black  spots  in  the  female.  The  fore  wings  are  sprinkled  with  dark 
spots  abundantly  in  the  female,  sparingly  in  the  male.  The  coral- 
winged  locust  (Fig.  169)  is  the  same  size  as  the  preceding,  the 


Fig.  167. — Puff  adder  or  hognosed  snake,  Heter- 
odon  platirhinos.    At  left  animal  is  rigid  in  a  "fit." 


ANIMALS  OF  THE  DUNES 


163 


base  of  the  inner  wing  is  bright  coral  red.  The  basal  half  of  the 
inner  face  of  the  hind  femur  is  Prussian  blue.  The  females  of 
the  straight-lance  and  sword-bearing  grasshoppers  are  provided 
with  long  ovipositors.  In  the  former  (Fig.  170)  the  ovipositor 
is  longer  than  the  hind  femur,  and  the  sides  of  the  body  are 
green.  In  the  latter  (Fig.  171)  the  ovipositor  about  equals  the 
length  of  the  hind  femur,  and  also  the  length  of  the  body. 
Among  the  insects  no  group  exhibits  more  sharply  defined 
zonal  limitations  than  the  orthoptera.  •  While  some  species  are 
cosmopolitan,  the  majority  are  found  only  in  definite  situations 


Figs.  168-171:  Fig.  168. — Sprinkledlocnst,  ChloeaUis  cons  persa;  Fig.  169. — 
Coral-winged  locust,  Hippiscns  tuhcrculatiis;  Fig.  170. — Straight-lance  grass- 
hopper, Xiphidium  strictmn;  Fig.  171. — Sword-bearing  grasshopper,  Conocephaliis 
ensiger. 

with  clearly  marked  borders  that  are  rarely  overstepped.  One 
might  name  many  of  the  associations  with  the  characteristically 
present  orthoptera.  Thus,  the  digger  w^asp  association  might  be 
called  the  maritime  locust  association.  The  bronze  tiger  associa- 
tion could  be  quite  justly  called  the  narrow-winged  locust  asso- 
ciation, while  the  ant-lion  association  might  be  designated  the 
coral-winged  locust  association. 

Both  in  this  and  the  succeeding  association  the  oaks  are 
attacked  by  gall  flies  and  other  gall-forming  insects  that  rear 
their  young  in  the  different  sorts  of  galls  induced  by  their  ovi- 
position.  Such  galls  seem  to  be  more  abundant  on  the  dunes 
than  elsewhere.  Some  thirty  different  sorts  can  be  collected 
on  the  oaks  in  this  and  the  succeeding  mixed  oak  association, 


1 64       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Fig.  172. — Six  typical  oak  galls  (from  Felt):  a,  Spong>'  oak  apple,  Amphi- 
bolips  confluentus;  b,  Hollow  oak  apple,  A.  inanis;  c,  Woolly  leaf  gall,  Ajidricus 
flocci;  d,  Oak  fig  gall,  Biorhiza  forticoniis;.  e,  Woolly  stem  gall,  Callirhytis  setni- 
nator;  /,  Knot  gall,  C.  punctatus. 


ANIMALS  OF  THE  DUNES 


165 


including  the  oak  apple,  the  empty  apple,  the  petiole  gall,  the 
wool  gall,  the  midrib  gall,  the  bullet  gall,  the  seed  gall,  etc. 
(Fig.  172). 

With  the  advent  of  the  red  and 
white  oaks  in  the  mixed  oak  asso- 
ciation conditions  begin  to  approxi- 
mate those  of  the  mesophytic 
climax  forests,  the  oak-hickory  and 
the  maple-beech.  The  soil  is  well 
supplied  with  humus.  The  shade 
is  deep  enough  to  prevent  excessive 
evaporation  and  to  afford  cover  for 
the  pioneers  of  that  whole  group  of 
animals  that  belong  to  the  cool, 

,1  •     ,  r   4.1,  Fig.  173. — Tree  toa.d,  Hylaversicolur 

dark,  moist  recesses  of  these  ^  -^ 

climax  forests.     Earth-worms  begin  to  appear.    The  holes  of  the 

woodchuck  are  common  and  the  mole  exca- 
vates his  subterranean  passages.  Such  snails 
as  Zonitoides  arboreus,  Polygyra  thyroides,  and 
P.  profunda  are  found  under  the  bark  of  de- 
caying trees,  under  logs,  or  crawling  on  the 
shrubs  in  moist  weather.  They  are  by  no 
means  so  common  as  they  are  in  the  later 
association.  jNIillipedes  and  centipedes  are 
found  under  the  bark  of  old  logs.  The  car- 
penter ant  makes  its  chambers  in  the  decay- 
ing logs  and  stumps,  and  the  aphid  housing 
ants  use  such  passages  as  stables  for  their 
'^cows, "  the  plant  lice;  it  carries  these 
Fig  174.— Tree  throughthe  winter  in  such  sheltered  retreats 
toad,  Hyla  pickeringii.  so  it  can  pasture  them  out  in  spring  on  the 
tender  vegetation.  Herbaceous  plants  are  now  numerous,  and 
there  is  an  abundant  insect  population  on  them.  Bumblebees, 
honeybees,  and  wasps  are  common.  Butterflies  are  abundant — • 
the  monarch,  viceroy,   spangled  fritillary,   w^ood   satyr,   wood 


i66        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

nymph,  anglewing,  mourning  cloak,  red  admiral,  Edward's  hair- 
streak,  the  zebra  swallowtail,  and  the  spicebush  swallowtail,  etc. 
The  tree  frogs,  Hyla  versicolor  (Fig.  173)  and  H.  pickeringii  (Fig. 
174),  are  common  on  the  shrubs  and  tree  trunks.  They  are  so 
striking  an  addition  with  their  birdlike  peeps  that  the  black  oak- 
red  oak  association  is  known  on  its  animal  side  as  the  Hylodes 
association.  The  walking  stick  is  frequently  shaken  from  the 
foliage  of  the  oak  in  late  summer.  The  tree  cricket,  Oecanthus 
angustipennis ,  and  stinkbug  are  also  com^monly  found  on  the 
red  oak  leaves.  The  former  is  a  pale  green  insect  with  gauzy 
wings  and  long  antennae  wath  black  dots  on  the  basal  joints  of 
the  antennae.  The  red-tailed  and  red-shouldered  hawks  sail 
over  this  territory  and  nest  in  the  big  trees.  The  red-headed 
woodpecker,  wood  pewee,  crow,  blue  jay,  bluebird,  least  fly- 
catcher nest  in  the  trees,  and  the  black  and  white  creeping  war- 
bler, the  yellow  warbler,  the  wood  thrush  nest  in  the  shrubs. 
The  gray  and  fox  squirrels  are  present. 

All  these  animals  of  the  hylodes  association,  while  strikingly 
new  if  this  zone  is  entered  from  the  lake  side,  are  old  familiars 
if  the  area  is  approached  from  the  other  direction,  for  they  are 
all  even  more  common  in  the  mixed  oak-hickory  association. 
The  oak-hickory  and  the  maple-beech  forests  are  the  climax 
mesophytic  forests  and  will  be  considered  in  a  succeeding 
chapter. 


CHAPTER  IX 


INTERDUNAL  PONDS  AND  TAMARACK  SWAJ^IPS 

S  THE  dunes  are  a  series  of  sand  ridges, 
more  or  less  parallel  to  the  lake  shore,  so 
between  them  there  lies  a  corresponding 
series  of  valleys,  often  steep  sided  with 
interdunal  ponds,  swales,  or  swamps 
(Fig.  175)  in  their  bottoms  according 
as  these  are  low  enough  to  reach  or 
i^  nearly  reach  the  water  level.  Since  the 
newer  dunes  are  close  to  the  lake,  so  also  are  the  new  interdunal 
ponds,  while  those  farther  and  farther  back  from  the  lake  are 
of  greater  and  greater  age. 

Now  it  is  the  fate  of  the  permanent  pond  among  the  hills 
to  fill  up  and  disappear.  Rains  wash  soils  down  into  it,  plants 
grow  in  its  waters  and  along  its  margins,  and  their  accumulating 
remains  fill  it  with  vegetable  debris  that  does  not  have  time  to 
decompose  before  the  next  season's  luxuriant  growth  is  piled 
upon  it.  The  black  muck  at  the  bottom  of  the  pond  rises  ever 
nearer  the  surface;  its  lower  layers  transform  to  peat.  Plants 
that  grow  on  sandy  bottoms  are  replaced  by  those  that  grow 
on  muddy  bottoms.  Deep-water  plants  give  rise  to  shallow- 
water  forms.  Those  plants  characteristic  of  the  margins 
advance  toward  the  center.  So  the  pond  transforms  to  marsh 
and  the  marsh  to  low  prairie  or  wet  woodland.  (See  chap,  xi 
also.)  These  stages  gradually  ensuing  with  the  characteristic 
accompanying  plants  and  animals  may  each  be  studied  in 
these  interdunal  ponds,  beginning  with  those  near  the  shore 
and  working  back  to  the  later  stages. 

Ponds  near  the  lake  shore  are  in  a  condition  similar  to  the 
central  portions  of  shallow  lakes  and  ponds  farther  inland,  which 

167 


1 68       .4  NATURALIST  IN  THE  GREAT  LAKES  REGION 


portions  have  not  yet  been  invaded  by  plants.  A  little  farther 
back  are  interdunal  ponds  stocked  with  Chara;  then  come  others 
with  such  plants  as  Myriophylliim  and  its  associates,  all  forms 
with  finely  dissected  leaves.  These  plant  populations  are  similar 
to  the  zones  shoreward  from  the  bare-bottomed  area  in  shallow 
lakes.  So  the  successively  older  dune  ponds  are  comparable 
to  the  successive  zones  of  plant  and  animal  forms  in  the  fiUing 
inland   lakes.     The  older  ponds',  if  good-sized,  will  naturally 


Fig.  175. — Interdunal  swale  01  the  iirst  type 

themselves  contain  several  zones,  though  smaller  ones  may  be 
completely  occupied  by  the  bulrush  stage,  the  cat-tail  stage  or 
by  similar  plants  characteristic  of  some  one  zone  of  the  larger 
filHng  pond. 

The  very  new  pond  in  the  dune  region  is  but  a  recent  cut- 
off from  the  lake.  Its  bottom  is  sandy;  no  plants  have  as  yet 
secured  a  foothold.  There  are  present  a  few  fish  that  find  its 
quiet  waters  good  places  to  lay  their  eggs;  these  must  find  access 
by  some  channel  connecting  with  the  lake.  The  fish  commonly 
found  in  such  a  pond  include  the  pike,  the  red  horse,  the  Cayuga 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS       169 


minnow,  and  the  shiner.     There  are  also  present  some  clams, 

notably  Lampsilis  luteola,  Alasmodonta  marginata  and  Anadonta 

grandis,  the  first  confined  to  the  very  new  ponds,  the  other  two 

occurring  also  in  those  somewhat  older.     There  are  found,  too, 

such  insects  as   the  caddis  worm    (Go era) 

(Fig.  176)  nymphs  of  the  damsel  flies  of  the 

genus  Lestes  and  of  the  dragon  flies  Tramea 

lacerta    and    Celethemis   eponina,    the   water 

boatman,  and  occasional  diving  beetles  that 

fly,  frequently  seeking  new  territory  in  which 

to    hunt.      The   caddis-fly,    damsel-fly,    and 

dragon-fly   nymphs   are    characteristic,    the 

others  cosmopolitan. 

The  damsel-fly  nymphs  are  long,  slender, 
and  bear  three  diverging  gill  plates  at  the 
posterior  end  of  the  body.  Nymphs  of  Lestes  ^^'^'"  ^''''^'  Enlarged. 
(Fig.  177)  are  recognized  by  the  form  of  the  so-called  accessory 
jaws  (Fig.  178),  really  labial  palps,  on  the  extensible  mask 
of  the  head,  which  is  the  much  modified  lower  Hp  or  labium. 


Fig.  176.— Caddis-fly 


1 


1 

Fig.  177. — Nymph  of  damsel  fly,  Lestes  for  cipatus.     Enlarged.    After  Needham 


Each  ''jaw"  has  two  processes,  "one  of  them  resembling  a 
fork  with  the  median  tines  broken  off,  the  remaining  process 
consisting  of  a  long  non-bifurcate  projection  with  a  short,  hairy 
hook  at  the  distal  end  and  minute  teeth  along  the  mesal  margin." 
The  nymph  of  Tramea  lacerta  is  green  with  brown  markings. 
The  legs  are  long  and  thin.  The  spines  of  the  eighth  and  ninth 
segments  are  very  long.     The  nymphs  of  C.  eponina  (Fig.  179) 


1 70        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Fig. 178 


have  very  prominent  eyes,  a  very  large  labium,  and  the  abdomen 
is  scarcely  narrowed  at  all  until  the  ninth  segment.  There  is  a 
black  band  between  the  eyes  and  a  black  band  encirchng  each 

femur.  The  adult  Lestes  is  rather  dull  colored, 
and  when  it  rests,  the  wings  are  held  as  a  rule 
spread  horizontally  rather  than  folded  over  the 

back,  as  other  damsel  flies  hold 
theirs.  The  full-grown  dragon  fly 
of  Tramea  lacerta  has  a  wing- 
spread  of  nearly  4  inches.  The 
body  is  dark,  almost  black.  The 
"A"'  upper  surface    of   the  abdomen 

^  „  ,,.      '  '^  -r         bears  white  or  sfreenish  spots.    It 

Figs.  178,  179:     Iig.  178. — ^Jaws     ^  r 

of  nymph  of  Lestes  forcipatus,  after  ^les  from  June  to  September. 
Xeedham;    Fig.  179.— Nymph    of    C.  eponina  (Fig.  180)  has  a  wing- 

dragon  fly,  Celethemis  eponina.  ^^xQ^d  of    about  3   inches.      The 

thorax  is  red-brown  with  black  stripes.     The  abdomen  is  black 

with  yellow  spots.     The  triangle  is  covered  with  a  spot,  and 

there  are  two  bands, 

sometimes  reduced  to 

spots,  on  each  wing. 

It  also  flies  from  June 

to  September. 

Lampsilis  luteal  a 
(Fig.  181)  has  a 
smooth  shell  with 
distinct  narrow  green 
rays.  It  is  about 
twice  as  long  as  high. 
It  is  good  sized, 
usually  3r5  inches  long  and  quite  thick.  The  muscle  scars  and 
cardinal  teeth  are  plain  on  the  inside  of  the  shell. 

Alasmodonta  marginata  (Fig.  182)  is  rayed  with  broad  green 
radiating  lines.  In  outline  it  is  quadrate,  the  posterior  region 
being  truncate.     The  umbones  are  marked  by  three  distinct 


Fig.  180. — Adult  dragon  fly,  Celethemis  eponina. 
After  Needham. 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS      171 


and  one  feeble  double-looped  ridges  directed  forward.  It  is 
usually  not  over  3  inches  long.  Anadonta  grandis  (Fig.  183)  is  a 
large  clam  3-7  inches  long.  The  shell  is  generally  thin;  the 
muscle  scars  are  not  clear.  The  color  is  dark  green  to  black. 
There  may  be  rays  on  the  young  shell.  The  umbones  bear 
double-looped  ridges. 

The  common  pike  (Fig.  184)  is  a  slender  fish  up  to  36  inches 
in  length.     The  head  has  no  scales  on  its  upper  portion.     The 


181 


182  ^^^^"-^  tl^3 

Figs.    181-183:    Fig.   181. — Shell  of  clam,   Lampsilis  luteola;    Fig.    182. — 
Alasmodonta  marginata;  Fig.  183. — Anadonta  grandis. 

mouth  is  very  large,  one-half  the  length  of  the  head.  The  red 
horse  is  one  of  the  suckers  all  good-sized  fish  recognize  by  the 
snouty  head  and  the  ventral  position  of  the  mouth.  The  lips 
in  this  species  are  strongly  phcate.  It  is  a  very  widely  distrib- 
uted form.  The  Cayuga  minnow  and  the  common  shiner  are 
both  minnows  belonging  to  the  genus  Notropis.  The  minnows 
are  usually  small,  3-4  inches  long,  have  very  large  scales  in 


172       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


proportion  to  their  size  so  that  there  are  less  than  40  in  any  one 
of  the  rows  running  the  length  of  the  body.  The  Cayuga  minnow 
is  about  2.5  inches  long,  oHvaceous  in  color.  The  scales  of  the 
lateral  line  are  each  marked  with  a  crescentic  black  area,  thus 


Fig.  184. — The  common  pike,  Esox  lucius,  one-eighth  natural  size 

breaking  the  lateral  line  into  a  series  of  crossbars.  The  common 
shiner  (Fig.  185)  has  more  than  eight  rays  in  the  ventral  fins. 
The  dorsal  fin  is  either  directly  over  or  slightly  in  front  of  the 
ventrals.  The  color  of  the  fish  is  olivace- 
ous, silvery  below;  the  males,  however,  in 
spring  have  the  sides  a  rich  salmon  pink, 
and  in  summer  the  oHvaceous  has  a  steel- 
blue  luster. 

The  first  plant  to  invade  these  ponds 
is   usually   the   chara,  an  alga  with  its 


\4L^ ■■ 


Fig.  185  Fig.  i86 

Figs.  185,  186:  Fig.  185. — The  shiner,  Xotropis  atherinoides,  one-half  natural 

size;  Fig.  186. — Chara,  reduced  one-half. 

• 

smaller  branches  whorled  (Fig.  186).  It  fastens  itself  to  the 
bottom  and  grows  up  in  a  perfect  tangle  of  green.  This  plant 
thrives  best  in  the  undrained  ponds,  but  still  is  found  in 
those  with  some  connection  with  the  lake.  It  contains  in 
its  tissues  much  silica  so  that  it  feels  harsh  when  crushed 
in  the  hand,  and  when  pulled  out  of  the  pond  it  has  a  rank 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS 


173 


odor.  It  grows  with  great  rapidity,  covering  the  bottom 
and  growing  up  in  the  w^ater,  although  not  to  the  top.  While 
the  chara  is  getting  a  foothold  and  covers  the  bottom  only 


Fig.  187. — The  bluegill,  Lcpomis  pallldus,  reduced  one-half 


Fig.  188. — Pumpkin  seed,  Eupomotis  glbbosus.     After  Forbes 

partially,  leaving  bare. spots,  the  bluegill  (Fig.  187)  and  pumpkin 
seed  (Fig.  188)  are  found  hiding  among  its  tangles  and  nesting 
in  the  bare  places.     The  clams  and  caddis  flies  before  mentioned 


174       ^  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Fig.  189.— 
Nymph  of  the 
dragon  fly,  Gom- 
phus  spicatus. 


persist  under  such  conditions.  The  burrowing  dragon-fly  nymph 
(Gomphus  spicatus)  finds  the  somewhat  muddy  bottom  congenial. 
As  the  chara  takes  complete  possession  its  tangled  growth  fur- 
nishes a  safe  hiding-place  for  a  new  lot  of  fish — 
mud  minnows,  golden  shiners,  the  chub  sucker, 
the  bullhead,  and  the  tadpole  cat. 

The  nymph  of  G.  spicatus  (Fig.  189)  when  full 
grown  is  over  an  inch  long.  The  body  is  flat, 
hairy  on  the  margins,  and  the  legs  are  hairy. 
The  abdomen  tapers  gradually  to  a  point.  The 
color  is  green,  the  eyes  black.  The  adult  flies  in 
May  and  June. 

The  mud  minnow  (Fig.  190)  is  about  4  inches 
long.  The  upper  parts  are  brownish  olive, 
mottled  with  black.  The  sides  are  barred  in  dark  with  bluish 
intervals,  underside  yellow,  fins  olive  green.  The  golden  shiner 
(Fig.   191),   also   called 

bream    or  roach,   is  6-8  .^.^r^wm^W^^^ws^^^^^: ^ 

inches    long    when    full  ^^^"h^M^^^^^-WW^^ 
grown.   The  body  IS  deep,  .  «^*^*  .^ -^... ,  .  v.   _ 

compressed,  and  tapers 

both    toward    head    and        Fig.  190.— Mud  minnow,  rw5m /fw^,  reduced 

tail.     The  head  is  small.  ^^^' 

The  lateral  line  sags  distinctly.     The  color  is  dark  olive  green. 

The  sides  are  silvery  with  golden  reflections.  ' 

In  the  chub  sucker  (Fig.  192)  the  dorsal  fin  is  short  and 
contains  from  ten  to  eighteen  developed  rays.  The  lateral  line 
is  wanting.  The  adult  is  only  some  10  inches  long.  The  color 
is  brownish-olive,  with  coppery  luster  above,  paler  below.  The 
young  are  longitudinally  striped,  the  most  conspicuous  color 
band  being  one  of  purplish  black  running  through  the  eye  and 
along  the  side  to  the  caudal  fin.  Below  this  the  sides  shade  off 
to  a  white  or  silvery  belly. 

The  bullheads  and  catfishes  have  fleshy  projectors,  ''feelers" 
or  barbels  about  the  mouth.     The  brown  bullhead  (Fig.  193)  has 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS      175 


Fig.  igi. — Golden  shiner,  Ahramis  crysoleucas, 
reduced  one-half. 


twenty-two  or  twenty- three  rays  in  the  anal  fin,  including  rudi- 
mentary ones.  It  reaches  18  inches  in  length,  though  it  is  usually 
much  smaller.  The  color  is  dark  yellow-brown  to  black  above, 
usually  mottled;  below 
it  is  gray,  pink,  or 
white.  The  lower 
barbels  are  similarly 
colored.  The  black 
bullhead  is  found  in 
the  older  ponds. 

The  tadpole  cat 
(Fig.  194)  is  a  small 
fish,  3-5  inches  long, 
with  a  thick,  fleshy  head,  so  it  does  have  something  the  shape 
of  a  tadpole.  It  is  dark  olivaceous  above,  yellow  below.  The 
dorsal  fin  has  a  spine  at  its  forward  edge,  which  is  more  than 

half  the  height  of  the  fin. 

The  chara  in  the  un- 
drained  ponds,  as  well  as 
those  in  connection  with  the 
lake,  swarms  with  the  blood- 
red  larvae  of  Chironomus,  a 
midge.  These  bloodworms 
crawl  upon  the  plant  and 
build  tubes  in  which  they 
conceal  themselves  in  part. 
A  new  caddis-fly  larva  {Lep- 
tocera)  that  builds  a  long, 
slender  tube  of  tiny  sand 
grains,  replaces  the  one  that 
was  common  in  the  more  open  chara  beds.  In  the  deeper  parts 
of  the  chara,  red  water  mites,  Limnochares  aquaticus  are  abun- 
dant. Some  small  snails  (Amnicola  limosa  and  A.  cincinnalien- 
sis)  are  found  creeping  upon  the  plants  on  which  larger  snails  are 
also  frequently  present,  namely,  Physa  gyrina,  known  by  the 


Fig.  192. — Head  of  chub  sucker,  Erimy- 
son  sucetta. 


176       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

left-handed  coil  of  its  shell  and  the  fact  that  the  aperture  is  less 
than  two-thirds  the  length  of  the  shell,  Lymnaea  reflexa  and 
Planorhis  hicarinatus  (Fig.  324)  the  former  more  abundant  in  the 
older  ponds.  Lymnaea  humilis  and  L.  desidiosa  are  pretty  much 
confined  to  the  younger  ponds.  Planorhis  parvus,  P.  campanu- 
latus,  P.  hirsutus  are  occasionally  found  in  all  the  relatively  newer 


Fig.  193. — Brown  or  spotted  bullhead,  Ameiurus  nebulosus.     After  Forbes 

ponds.  Snails  of  the  genus  Amnicola  have  small  (.3  inch  or 
less)  conical  shells,  the  mouth  of  which  is  closed  w^hen  the  animal 
draws  back  into  its  shell  by  a  horny  close-fitting  disk,  the  oper- 
culum.    The  edge  of  the  opening  is  not  connected  with  the  body 


Fig.  194. — Tadpole  cat,  Schilbeodes  gyrinus 

of  the  shell.  In  A.  cincinnatiensis  the  aperture  of  the  shell  is 
nearly  half  as  wide  as  the  shell  is  long.  In  A .  limosa  the  round 
opening  is  pressed  quite  against  the  body  of  the  shell  which  is 
unusual  in  the  genus.  The  Lymnaeas  do  not  have  an  oper- 
culum. The  shell  is  long  with  six  or  so  whorls.  L.  reflexa  is 
.8  to  1.6  inches  long.  The  spire  is  longer  than  the  aperture. 
The  edge  of  the  aperture  is  strongly  turned  back.     L.  humilis  and 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS      177 


L.  desidosa  are  small,  .6  inch  long  or  less.  The  former  has  a 
short  conic  spire  with  an  aperture  produced  below,  the  latter, 
a  long,  tapering  spire  and  the  aperture  not  produced.  As  the 
name  indicates  the  whorls  of  Planorhis  are  in  one  plane,  so  the 


Fig.  195, — Nymphoi  damsel  Ry,  I schnuraverticalls.    Enlarged.    After Needham 

shell  is  flat.  The  mouth  of  the  shell  flares  bell-like  in  P.  campanu- 
latus.  P.  hirsutus  and  P.  parvus  are  small, .  25  inch  or  less  in  diam- 
eter.   In  hirsutus  the  shell  is  covered  with  short,  bristly  hairs. 


■A      *  .'  A.  *  - 


Fig.  196. — Buttonbush,  Cephalanthus  occidenlalis ,  pushing  out  into  pond 

In  P.  parvus  both  sides  of  the  shell  (really  top  and  bottom) 
are  equally  concave.  A  small  crustacean,  a  bender  (Hyalella 
knickerbockeri)  is  abundant,  especially  in  the  spring.  In  general 
appearance  it  is  much  like  Gammarus  fasciatus  (Fig.  56),  but 
while  Gammarus  swims  on  its  side  constantly,  Hyalella  does 


178        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


so  only  about  half  the  time,  going  ventral  side  up  the  other 
half  of  the  time.  Eucrangonyx  gracilis  swims  on  its  back  all  the 
time.  It  is  found  in  the  old  forest  ponds.  Another  crustacean 
inclosed  in  a  bivalve  shell  like  a  small  clam  is  found  abundantly 
on  the  bottom  {Cypris,  Fig.  56).  The  musk  turtle  is  a  frequent 
and  distinctive  inhabitant  of  these  chara  ponds.     Its  odor  is 

quite  enough  to  distinguish  it. 
Chara  ponds  do  not,  as  a  rule, 
support  a  varied  or  abundant 
animal  population,  for  the 
chara  is  not  an  attractive  food 
plant. 

As  the  chara  grows  and 
its  lower  layers  decompose, 
it  forms  peat  rapidly,  i  or 
2  inches  a  year,  so  that 
ponds  tend  to  fill  up  speedily. 
Then  flowering  plants,  with 
submerged  stems  and  leaves, 
the  latter  much  dissected, 
replace  the  chara.  Their 
flowers  are  reared  above  the 
surface.  Such  plants  are  mil- 
foil, bladderwort,  pond  weed 
(Fig.  64),  and  their  associates, 
to  be  described  more  in  detail 
in  chapter  xi. 


Fig.  197. — Pennsylvania  saxifrage, 5aA;z'- 
fraga  pennsylvanica. 


The  nymph  of  the  damsel  fly,  Ischnura  verticalis  (Fig.  195), 
is  quite  characteristic  of  these  milfoil  ponds  in  the  Dunes, 
though  it  is  a  very  widely  distributed  species  elsewhere.  The 
nymph  may  be  recognized  by  the  fact  that  its  gill  plates  end 
in  a  long,  tapering  point  and  bear  one  or  two  dark  crescentic 
crossbands. 

The  adult  male  of  Ischnura  verticalis  is  green  with  the  top  of 
the  abdomen  black.      The  females  may  be  either  black  or  orange 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS      179 


and  they  have  black  spots  near  the  tips  of  both  wings;  the  fully 
matured  males  have  the  spots  on  the  front  wings  only.  Other 
forms  to  be  listed  below  are  also  found  here  in  the  Myriophyllum 
ponds,  though  not  as  abundantly  as  a  rule  as  in  the  later  ponds. 

The  newer  ponds  of  the  dunes  may  then  be  described  in 
order,  naming  them  both  from  the  characteristic  animals  and 
plants:  (1)  the  Lam p- 
silis  liiteolus  ponds  or 
bare-bottomed  ponds; 
(2)  bloodworm  ponds 
or  Char  a  ponds;  (3) 
Ischnura  ver  tic  alls 
ponds  or  bladderwort- 
milfoil  ponds. 

The  older  ponds 
are  usually  them- 
selves distinctly  zon- 
ated  and  must  be 
described  in  terms  of 
zonally  arranged 
plant  and  animal  soci- 
eties rather  than  as  a 
single  society.  Yel- 
low and  white  water 
Hlies  appear  shore- 
ward from  the  sub- 
merged plants,  then 


Fig.  198. — The  sensitive  fern,  Onoclca  sensibilis, 
underground  stem  and  all. 


come  rushes,  cat-tails,  sedges,  and  so  the  filling  chara  ponds 
give  rise  to  marshy  or  swampy  areas  that  seem  to  evolve  into 
three  different  types  of  regions,  the  differences  depending 
primarily  on  drainage,  namely,  (i)  the  wet  forest,  (2)  the  prairie, 
and  (3)  the  tamarack  swamp. 

In  the  first  type  (Fig.  175)  grasses  and  sedges  grow  along 
the  margins,  and  with  them  are  such  plants  as  the  buttonbush, 
the  sensitive  fern,  marsh  marigold,  white  violet,  and  the  swamp 


i8o       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


saxifrage.  The  buttonbush,  or  elbow  bush  (Fig.  196),  is  a  low 
shrub  with  abruptly  bent  branches,  which  give  it  the  name  elbow 
bush.  It  bears  large,  egg-shaped  leaves,  rather  pointed  at  both 
ends.  The  flowers  which  are  small  and  white  occur  in  spherical 
clusters.  The  marsh  marigold  or  cowslip  is  familiar  to  almost 
everyone.  Swamp  saxifrage  (Fig.  197)  has  long,  slender,  lance- 
shaped  leaves  that  are  mostly 
basal;  their  borders  are 
toothed.  The  clustered  flow- 
ers are  yellowish  green  on  long 
slender  stalks.  Sensitive  fern 
is  so  unlike  the  other  ferns 
of  the  region  that  it  may  be 
readily  recognized  from  Fig. 
198.  The  leaf  is  roughly 
triangular  and  cut  into  large 
lobes,  not  finely  dissected  as 
are  most  of  the  fern  leaves. 
It  is  very  sensitive  to  frost 
and  dies  in  the  early  fall. 

Still  farther  out  on  the 
margin  will  be  found  a  group 
of  plants  that  is  common  at 
the  outer  edge  of  all  the 
marshes — sour  gum,  the 
small-toothed  trembhng  pop- 
lar, swamp  holly,  tw^o  species 
of  Spiraea,  the  wdntergreen,  the  cinnamon  fern,  Clayton's  fern, 
and  the  royal  fern. 

Sour  gum  (Fig.  199)  is  a  deciduous  tree  that  has,  as  a  rule,  a 
trunk  that  runs  straight  to  the  top,  as  does  the  trunk  of  a  pine. 
The  lower  branches  droop  so  that  the  tree  has  quite  the  appear- 
ance of  a  conifer.  The  small-toothed  trembling  poplar  has  the 
characteristic  yellowish-green  bark  of  the  poplars.  Its  leaves 
are  small,  finely  toothed,  and  are  borne  on  leafstalks  that  are 


Fig.  199. — Sour  gum,  Nyssa  sylvatica 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS       i8i 


vertically  flattened.  When  not  in  leaf  the  tree  may  be  recog- 
nized by  the  rounded  leaf  buds  that  are  smooth.  Swamp  holly 
(Fig.  200)  is  a  shrub  with  alternate  simple  leaves  which  are 
coarsely  toothed  but  not  spiny,  as  is  suggested  by  the  name  of 
holly.  The  fruits  are  red  berries,  as  in  the  familiar  Christmas 
holly,  but  they  are  not  clustered.  They  grow  thickly,  however, 
on  the  shrub  and  persist  through  the  early  part  of  the  winter. 
Spiraea  latifolia  (Fig.  201),  commonly  known  as  meadow- 
sweet, is  another  low  shrub  with  simple  alternate  leaves  that  are 


c^^ 


Figs.  200-202:  Fig.  200. — S\Yaimp  hoWy,  Ilex  verticillata;  Fig.  201. — Meadow- 
sweet, Spiraea  latifolia;   Fig.  202. — Steeplebush,  5.  tomentosa. 

lance-shaped  and  sharply  toothed.  The  flowers,  which  occur 
in  pyramidal  clusters,  are  pink  or  pinkish  white.  Spiraea 
tomentosa  (Fig.  202),  or  steeplebush,  is  a  still  more  slender  shrub, 
usually  unbranched,  the  stem  being  covered  with  silvery  hairs. 
Conical  clusters  of  pink  or  purplish  flowers  make  it  a  conspicuous 
and  attractive  plant.  Clayton's  fern,  also  called  the  interrupted 
fern,  the  cinnamon  fern,  and  the  royal  fern  are  closely  related 
species  of  the  genus  Osmunda.  The  royal  fern  (Fig.  203)  has 
leaves  that  are  two  or  three  times  compounded.  The  spore 
cases  are  borne  at  the  tips  of  the  leaves.     The  interrupted  fern 


i82       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


(Fig.  204)  has  a  long  and  rather  narrow  frond  with  long  and 
narrow  leaflets.  Certain  leaflets  in  the  middle  of  the  frond  are 
altered  to  bear  the  spore  cases. 
The   fronds   of  the   cinnamon 


Fig.  203 
Figs.  203,  204:  Fig  203. 
fern,  Osmimda  Claytoniana. 


Fig.  204 
-Royal  fern,  Osmunda  regalis;  Fig.  204. — Clayton's 


Fig.  205. — Cinnamon 
fern,  Osmunda  cinna- 
momea,  spore-bearing 
frond  at  left. 


fern  (Fig.  205)  are  similar  to  those  of  the 
interrupted  fern,  but  have  their  stalks 
covered  in  youth  with  cinnamon-colored 
scales.  The  spore-bearing  fronds  and  the 
vegetative  ones  are  separate,  the  former 
being  devoted  entirely  to  the  spore  cases 
and  appearing  quite  unlike  fern  leaves. 

In  the  second  type  of  pond  (Fig.  206) 
bulrushes  encroach  upon  the  pond  Hlies, 
then  comes  a  zone  of  sedges  and  grasses 
and  a  few  willows,  mostly  the  shiny-leaved 
willow.  Still  farther  shoreward  come  the 
iris,  the  blue-eyed  grass  (Fig.  102),  the 
yellow-eyed  grass,  the  arrow-leaved  violet 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS       183 


(Fig.  131),  and  the  lance-leaved  violet,  grass-of -Parnassus,  and 
the  painted  cup.  Round  the  margins  in  addition  to  the  shiny- 
leaved  willow  one  finds  the  red-osier  dogwood,  the  shrubby 
cinquefoil,  and  St.  John's-wort. 

Grass-of-Parnassus  has  heart-shaped  basal  leaves  1-2  inches 
Jong  with  five  conspicuous  veins  that  run  from  end  to  end  of  the 
leaf.  The  flower  stalk  bears  a  single  conspicuous  white  flower, 
bearing  several  greenish  veins.     The  flower  is  about  an  inch  in 


mrm 


Fig.  206. — Interdunal  pond  of  second  type 

diameter.  Painted  cup  is  rather  tall  and  conspicuous  because 
of  the  bright  scarlet  bracts  among  the  flowers,  giving  the  plant 
the  appearance  of  a  paintbrush  dipped  in  red  paint.  Red- 
osier  dogwood  is  a  shrub  with  bright  red  stems,  quite  slender, 
and  very  phable.  Shrubby  cinquefoil  (Fig.  207)  is  a  low, 
tufted  shrub  with  bark  that  shreds  off  readily.  The  leaves  are 
palmately  compound,  with  five  or  sometimes  seven  leaflets. 
The  flowers  are  yellow,  about  an  inch  across. 

The  animals  found  in  these  two  types  of  ponds  are  practically 
identical.     In  the  deeper  waters  are  found  small  clams  of  the 


i84       A  NATUILILIST  IN  THE  GREAT  LAKES  REGION 

family  Sphaeridae  (Fig.  2q8)  .     One  thinks  on  first  sight  that  these 

are  the  young  of  the  larger  clams, 
but  such  disappear  from  the  dune 
ponds  with  the  replacement  of  the 
sandy  bottom  by  the  muddy  bottom. 
In  the  Sphaeridae  the  lateral  teeth 
of  the  shell  are  found  on  both  sides 
of  the  cardinal  teeth,  while  in  the 
larger  clams  they  occur  on  one  side 


Fig.  207  Fig.  208 

Figs.  207,  208:  Fig.  207. — Shrubby  cinqxieh'A,  Polenlilla  friiticosa;  Fig.  208. 
A  small  clam,  Sphacriiini  simile. 


Fig.  209. — Molt  skin,  nymph  of  Anax 


only.     A  few  mud-loving  fish  are  present,  like  the  black  bullhead, 
similar  to  the  spotted  (Fig.  193)  but  dark  brownish  or  greenish 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS       185 


Fig.  210. — Nymph  and  adult  of 
dragon  fly,  Leucorhinia  intacta. 
After  Shelf ord. 


black,  unspotted  or  nearly  so.  It  is  our  commonest  bullhead. 
The  mud  minnow  (Fig.  190)  is  also  present.  Many  damsel-  and 
dragon-fly  nymphs  are  present  in  the  marginal  zone,  and  the 
adults  are  found  hovering  over  the 
sedges  and  grasses.  Those  of  Lihel- 
lula  pulchella,  Gomphus  spicatus  (Fig. 
189),  Leucorhini  intacta,  and  Anax 
jiinms  occur  in  the  rush  and  cat- 
tail area. 

The  nymph  of  Anax  (Fig.  209)  K 
has  very  large  eyes  that  occupy  two- 
thirds  of  the  side  margin  of  the  head. 
The  adult  dragon  fly  appears  early 
in  spring,  and  flies  late  (late  March 
to  mid-October). 

The  eyes  of  the  adult  are  very 
large  also,  meeting  dorsally  for  some 
distance.     The  insect  is  good  sized, 
the  abdomen  some  2  inches  long.     The  color  is  green,  marked 
with  brown  and  blue  (male).     The  front  of  the  face  bears  a  dark 

spot  surrounded  by 
yellow  that  in  turn 
is  encircled  with  a 
blue  ring. 

The  nymph  of 
L.  intacta  (Fig.  210) 
is  mud-colored,  flat, 
and  the  abdomen 
terminates  abruptly. 
This  is  a  small  spe- 
cies, the  adult  hav- 
ing a  wing-spread  of  about  2  inches.  The  body  is  black.  The 
upper  part  of  the  face  is  ivory  white,  obscured  with  yellow  in 
the  female.  It  is  commonly  known  as  the  white-faced  dragon 
fly.     It  fhes  in  May  and  June. 


Fig.  211. 
Needham. 


-Dragon  fly,  Lihellula  pulchella.     After 


i86       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


a 


( 


Fig.  2 1 2A. — Some  aquatic  insects  and  nymphs.  After  P.  S.  Welch,  a,  stone-fly 
nymph;  i,  May-fly  nymph;  c,  whirhgig  beetle  larva;  </,  black-fly  larv'a;  e,  damsel- 
fly  nymph;  /,  water  tiger;  g,  larva  of  water  scavenger;  h,  the  dobson;  ?,  diving 
beetle;  j,  giant  waterbug;  ^,  smaller  waterbug;  I,  water-scavenger  beetle. 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS       187 


Fig.  212B. — Aquatic  insects  and  nymphs.  After  P.  S.  Welch,  a,  adult  mos- 
quito, b,  its  larva;  c,  its  pupa;  d,  water  skater;  c,  marsh  strider;  /,  whirligig  beetle; 
g,  water  scorpion;  h,  water  boatman;  /,  back  swimmer. 


i88        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


In  L.  pnlchella  the  mask  covers  the  most  of  face  in  the 
nymphs;  there  is  but  a  single  median  tooth  on  its  median  lobe. 
The  adult  is  (Fig.  211)  dark  brown  to  black  with  two  wide  green 
stripes  on  each  side  of  the  thorax  and  one  on  each  side  of  the 
abdomen.  The  triangle  of  both  fore  and  hind  wings  is  colored 
dark;  in  the  front  wing  its  long  axis  is  at  right  angles  to  the 
long  axis  of  wing  (July- August). 

Electric-light  bugs  or  waterbugs,  both 
great  and  small,  water  boatmen,  back 
swimmers  and  diving  beetles,  all  on 
Fig.  212,  A  and  B,  are  numerous.  The 
six-lined  diving  spider  (Fig.  213)  is  com- 
mon on  the  bulrushes.  The  common 
pond  snail  {Lymnaea  reflexa)  is  very 
abundant,  as  are  also  two  of  the  flat 
snails,  Planorhis  canipanulatus  and  Pla- 
norhis  parvus.  In  the  waters  of  such 
ponds  one  will  frequently  dredge  out 
many  of  the  little  efts,  Diemictylus 
viridescens   (Fig.  214).     In  the  bulrush 


hi       i  ul  J  Aw      .1  T   zone  and  farther  back  among  the  low 

Fig.  213.— The  diving    shrubs  the  large  garden  spider  (Fig.  215) 

spider,   Dolomcdcs  sexpnnc-    |^^-|^g    j^g    orb-shaped    webs    in     the 

Uitus.     After  Shelford. 

summer. 

In  the  late  summer  the  margins  of  such  ponds  and  swamps  are 

alive  with  grasshoppers  and  their  kind,  whose  stridulations  are 

incessant  in  such  a  location.     Earlier  in  the  season  the  grouse 

locusts  have  had  their  day.     They  are  small  animals,  less  than 

.  5  inch  long.     Tettix  granulatus  (Fig.  216)  is  moderately  slender, 

while    the    others  have  heavy  bodies.     Tettigidea  armata  and 

T.  parol pennis  were   common;    T.  lateralis   rare.     The   figure 

of  T.  lateralis  is  given  in  Fig.  216.     T.  parvipennis  is  much 

like  it,  but  the  middle  joints  of   the  antennae  are  less  than 

three  times  as  long  as  wide,  while  in  T.  lateralis  they  are  more. 

T.  armata  has  the  front  margin  of  the  thorax  (pronotum)  extend- 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS      189 


ing  in  a  point  between  the  eyes  nearly  to  their  fronts,  while  in 
the  other  two  species  mentioned  it  does  not  come  out  to  the 
mid-eye. 


Fig.  214. — The  eft,  Diemlctylus  viridesccns 


I90       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Now  the  ascendant  forms  on  the  rushes,  sedges,  and  shrubs 
at  the  pond  margins  and  in  the  swales  are  the  short-horned 


Fig.  215. — Garden  spider,  the  orb  builder,  Argiope 

locust ;  the  short-winged  green  locust  {Dichromorpha  viridus) ;  the 
slender-bodied    locust — rare — (Fig.    219);     the    Hoosier    locust 

(July);  Scudder's  par- 
oxya  (August)  ;  the 
leather-colored  locust; 
the  Nebraska  locust; 
a  striped  ground  cricket 
and  the  marsh  conehead 
(Fig.  225).  The  short- 
horned  locust  (Fig.  217) 
TP_      .     rp,  ,       +    T  /,•  1  ,       is  fairly  ojood- sized,  the 

riG.  216. —  Iht  gronstiocnsts,  1  ettix  graniilatiis  ^    g  '^ 

and  Tettigidea  lateralis.    After  Lugger.  male  measuring  .  8  inch 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS       191 


in  length;    the  female,  i  .3  inches.     They  are  bright  green  mot- 
lied  with  brown,  the  brown  sometimes  being  greatly  increased 


2.\1 


■A'l'.'^"  ' 


218 


m 


i 


w- 


2.2.0 


221 


Figs.  217-221:  Fig.  217. — The  short-horned  locust,  Tryxalis  hrevicornis;  Fig. 
'^18. — The  short-winged  green  locust,  Didiromorpha  viridus;  Fig.  219. — The  slender- 
bodied  locust,  Leptysma  marginicollis;  Fig.  220. — The  Hoosier  locust,  Paroxya 
hoosieri;  Fig.  221, — Scudder's  paroxya,  P.  scudderi,  male  (a),  female  {b).  All 
after  Blg,tchley. 


192       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

so  as  to  be  the  dominant  color.  The  antennae  are  strongly 
flattened  at  the  base.  The  mature  insects  are  found  from 
August  to  late  fall. 

The  short-winged  green  locust  (Fig.  218)  is  also  green 
marked  with  brown,  or  brown  with  green  markings.  It  is 
smaller  than  the  preceding,  the  male  being  about  .  6  of  an  inch 
long;  the  female,  sHghtly  over  an  inch.  The  adults  are  found 
as  early  as  mid- July. 


Figs.  222-225:  Fig.  222. — Striped  ground  cricket,  Kemohius  fasciatus;  Fig. 
223. — Leather-colored  locust,  Schistocerca  alutacea;  Fig.  224. — Nebraska  locust, 
Phaelaliotes  nehrascensis;   Fig.  225. — ]\Iarsh  conehead,  Conocephalus  palustris. 

The  male  of  the  Hoosier  locust  (Fig.  220)  is  quite  brightly 
colored.  The  face  is  green,  the  mouth  parts,  yellow.  The 
antennae  are  reddish  brown.  The  rest  of  the  animal  is  green, 
yellow,  and  black.  The  female  is  more  dully  colored.  The 
latter  is  1.25  inches  long,  the  male  not  quite  an  inch  long. 
The  antennae  are  very  long. 

Scudder's  paroxya  (Fig.  221)  is  small.  The  female  is  less 
than  I  inch  in  length;  the  male,  .6  of  an  inch.  The  general 
color  is  brown  with  green-yellow  markings.  An  ivory-white  line 
extends  back  from  the  eye;  above  it  a  broad  black  band. 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS       193 


The  leather-colored  locust  (Fig.  223)  is  yellowish  brown  to 
olive,  and  a  narrow  bright  yellow  line  runs  over  the  middle  of 


Fig.  226. — A  sphagnum  bog,  tamaracks  at  margin 

the  head  and  down  the  back.  The  male 
is  1.25  inches  long;  the  female,  nearly 
2  inches. 

The  Nebraska  locust  (Fig.  224)  has  a 
slender  body,  a  large  head.  It  is  olive 
green  marked  with  reddish  brown;  a  broad 
black  band  extends  back  from  each  eye. 
The  male  is  shghtly  less  than  an  inch; 
the  female,  slightly  more  than  an  inch  in 
length. 

The  striped  ground  crickets  (Fig.  222) 
are  only  about  .4  of  an  inch  long,  brown  fig.  227 
in  color,  with  dark  stripes  lengthwise  on     Figs.  227, 228:Fig.  227— 

,      .         ,       ^,  1      .T    1         1  The  slender  sedge,  Carcx 

the  head.     They  are  very  plentiful  and  are  ^^,y,,,,,^-,.  ^jg,  2  28.-The 

out  feeding  by  day.  shore  sedge,  C.  riparia. 


Fig.  228 


194       ^  NATURALIST  IN  THE  GREAT  LAKES  REGION 


The  third  type  of  swamp  found  in  the  dune  region  is  the 
sphagnum  bog  with  its  associated  border  of  tamaracks  (Fig. 

226).     It  is  one  of  the  most  striking  associa- 
tions of  plants  and  animals  to  be  found  in  the 


si        »■>>• 


'-fe 


Fig.  229  Fig.  230 

Figs.  229,  230:  Fig.  229. — The  orchis,  Arethitsa  hiilhosa;  details  of  blossom  at 
right.  Drawing  by  L.  N.  Johnson;  Fig.  230.— The  bearded  orchis  or  grass  pink, 
Calapogon  pulchellus.     Drawing  by  L.  N.  Johnson. 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS 


195 


Chicago  area.  It  is,  furthermore,  a  widely  distributed  associa- 
tion found  at  its  best  in  northern  North  America  and  Eurasia 
covering  very  wide  areas.     The  sphagnum  bogs  found  as  far 


232 


>».,\ 


233 


234 


235 


236 


Figs.  231-236:  Fig.  231. — The  sundew,  Droscra  rotundifoUa;  Fig.  232. — 
Tickseed,  Coreopsis  grandijlora;  Fig.  233. — Cottony  grass,  Eriophormn  gracile; 
Fig.  234. — Swamp  horsetail,  Equisetum  fluviatile,  and  section  of  stalk;  Fig.  235. — 
Swamp  fern,  Aspidium  Thclypterls,  and  under  side  of  one  pinnule;  Fig.  236. — 
Sphagnum  moss. 

south  as  the  Chicago  area  are  isolated  areas — islands  in  the  midst 
of  the  more  typical  associations.  As  will  be  seen  in  a  later  chapter 
they  are  probably  remnants  of  the  vegetation  that  was  quite  wide- 
spread in  this  region  immediately  following  the  glacial  period. 


196       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


In  the  center  of  such  a  sphagnum  bog  is  frequently  found 
a  small  lake  that  is  filUng,  and  this  may  be  occupied  in  part  by 
chara  (Fig.  186).  Quite  commonly  the  lake, 
if  it  is  sufficiently  deep,  will  have,  shoreward 
from  the  chara  zone,  a  zone  of  water  lilies, 
first  the  white,  then  the  yellow. 
The  water  shield  is  commonly 
found  growing  with  the  white 
water  lilies.  Next  comes  a  zone 
of  floating  sedges,  the  rhizomes 
of  which  mat  together  so  densely 
as  to  form  quite  substantial  foot- 


FiG,  237. — Ragged  orchis.  Habenaria  lacera,  details 
of  blossom  in  small  figures.    Drawing  by  L.  N.  Johnson. 

ing.  This  zone  of  floating  sedges  pushes 
farther  and  farther  out  into  the  lake  as  ice 
might  form  at  the  margin  of  a  pond.  The 
chief  mat-forming  sedge  is  Car  ex  filijormis 
(Fig.  227).     The  shore  sedge,  Carex  riparia 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS      197 


(Fig.  228),  is  often  found  associated  with  it.  Beyond  the  outer 
edge  of  the  sedge  mat  one  often  finds  bladderwort  (Fig.  64) 
growing  in  the  water.  As  one  walks  over  this  sedge  mat  the 
surface  heaves  up  and  down 
as  if  one  were  walking  on 
rubber  ice.  In  places  where 
the  sedge  mat  is  thin,  cat- 
tails are  hkely  to  be  growing. 
Farther  back  toward  shore 
where  the  sedge  mat  rests 
on  the  peaty  soil  a  number 
of  characteristic  plants  are 
to  be  found.  The  orchids 
are  present,  especially 
Arethusa  hulhosa  (Fig.  229) 
and  the  grass  pink,  Calapo- 
gon  pulchellus  (Fig.  230). 
The  sun  dew,  Drosera  ro- 
tundijolia  (Fig.  231)  is  a 
small  but  striking  plant. 
The  little  round  leaves  are 
covered  with  upright  glan- 
dular hairs,  at  the  tip  of 
each  of  which  is  a  drop  of 
sticky  substance  sparkling 
like  dew.     This  leaf  is  an 

insect  trap.  When  the  insect      ^         ^     ^         .  ,  j.   , .  o  • 

.       .         .  Fig.    238. — Fragrant    ladies  -tresses,  Spi- 

alightS  upon  it,  it  sticks  as  ranlhes  Romanzoffiana  (details  in  small  fig- 
it  would  to  fly  paper.      The    ^^^^s.)     Drawing  by  L.  N.  Johnson. 

leaf  then  closes,  the  tips  of  the  hairs  are  pressed  against  the 
body,  the  animal  is  digested,  and  the  plant  feeds  upon  the 
absorbed  organic  material.  The  other  plants  of  this  same  associa- 
tion are  the  swamp  milkweed,  known  by  its  milky  juice  and 
flowers  like  the  other  milkweeds,  the  marsh  bellflower,  tickseed. 
Coreopsis  grandiflora  (Fig.  232),  cottony  grass  (Fig.  233),  swamp 


igS       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

horsetail  (Fig.  234)  and  on  the  drier  parts  of  the  sedge  mat  the 
swamp  fern,  Aspidium  Thelypteris  (Fig.  235). 

Shoreward  from  the  sedge  zone  is  a  zone  in  which  the  ground 
stratum  is  marked  by  an  abundant  growth  of  sphagnum  moss 
(Fig.  236)  above  which  is  a  shrub  stratum  with  a  striking  group  of 
xerophytes,  the  most  conspicuous  of  which  is  the  leatherleaf, 
Chamaedaphne  calyculata  (Fig.  239).  The  zone  is  usually  called 
the  Cassandra  zone.  Sphagnum  is  a  pale  green  moss  whose 
spongy  tissue  holds  with  tenacity  an  immense  bulk  of  v/ater. 
It  forms  a  soft  carpet,  often  a  foot  deep.  Below  it  the  peaty 
soil  lies  to  a  depth  of  several  feet  usually  saturated  with  water 
and  very  cold.  The  soil  temperature  will  be  in  the  neighbor- 
hood of  50°  F.  in  midsummer,  even  on  days  when  the  air  tem- 
perature is  around  100°  F. 

Growing  in  the  sphagnum  one  finds  such  orchids  as  Arethusa 
(Fig.  229),  the  ragged  orchis  (Fig.  237),  fragrant  ladies'-tresses 
(Fig.  238),  together  with  cranberries,  both  large  and  small,  cot- 
tony grass,  and,  most  striking  of  all,  the  pitcher  plant.  This 
latter  is  another  of  the  queer  insectivorous  plants  found  in  this 
bog  region.  Its  vase-like  leaves  which  spring  in  clusters  from 
the  central  root  are  8  or  10  inches  long  and  are  lined  wdth  slippery 
hairs  pointing  down.  The  lip  of  the  vase  bears  a  ridge  of  succu- 
lent tissue  on  which  numerous  insects  feed  with  avidity.  In  their 
eagerness  they  sometimes  slip  off  into  the  pitcher  which  is  partly 
filled  with  water.  To  crawl  back  against  the  sharp  pointed  hairs 
is  not  easy.  So  the  bottom  of  the  pitcher  usually  contains  a 
more  or  less  concentrated  "insect  soup"  that  is  absorbed  by 
the  plant  and  serves  as  food  (Fig.  240). 

In  the  shrub  zone  besides  the  leatherleaf  sly eiound  Andromeda, 
chokeberry,  low  birch,  and  other  shrubs  of  similar  character. 
Andromeda  (Fig.  241)  is  a  low  evergreen  shrub  wdth  narrow 
leaves  that  have  their  edges  rolled  back  and  the  under  sides  of 
the  young  leaves  covered  with  a  white  varnish.  The  urn-shaped 
corolla  is  pink,  sometimes  white.  The  flowers  are  in  small  clus- 
ters (umbels). 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS       199 

Chokeberry  (Fig.  242)  is  a  shrub  a  yard  or  so  high.     The 
leaves  are  shiny  above,  paler  and  covered  with  fine  hairs  below. 


Figs.  239-244:  Fig.  239. — Leatherleaf,  Chamacdapkne  calyculata;  Fig.  240. — 
Pitcher  plant,  leaf  and  blossom,  Sarracenia  purpurea;  Fig.  241. — Andromeda, 
Andromeda  Polifolia;  Fig.  242. — Chokeberry,  Pyrus  arhutifolia;  Fig.  243. — Rush 
aster.  Aster  jnnceus;  Fig.  244. — Crested  shield  fern,  Aspidium  cristatum,  under 
side  of  one  pinnula  and  outline  of  sorus. 

The   flowers    are  like    apple   blossoms   and   grow   in   clusters. 

The  fruits,  like  small  red  apples,  are  .3  of  an  inch  in  diameter. 

One  famihar  with  the  birches  would  recognize  the  swamp 

birch  by  its  bark.     Its  leaves  are  egg-shaped,  rounded,  or  even 


200       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

kidney-shaped.  The  young  leaves  as  well  as  the  branches  are 
downy. 

Leatherleaf  shows  well  the  characteristics  of  this  group  of 
xerophytes.  Its  leaves  are  thick  and  glossy  with  the  wax  in 
the  epidermis;  the  under  side  of  the  leaf  is  scurfy — all  devices 
to  prevent  the  loss  of  w^ater.  One  wonders  at  such  xerophytic 
characters  in  shrubs  growing  in  a  swamp.  But  while  water  is 
abundant  it  seems  to  be  difficult  for  the  root  hairs  to  absorb 
it.  This  is  explained,  in  part  at  least,  by  the  low  soil  tempera- 
ture and  the  acidity  of  the  soil.  These  conditions  also  prevent 
the  decomposition  of  the  plant  debris  accumulating  from  season 
to  season,  since  they  check  the  activity  of  the  soil  bacteria  so 
necessary  for  this  process.  This  debris  accumulates,  therefore, 
as  peat  instead  of  decomposing  to  help  form  humus  as  it  would 
in  most  soils. 

Next  to  the  cassandra  zone  comes  the  tamarack  zone 
(Fig.  226)  with  tamarack  or  larch  trees  as  the  most  conspicuous 
plants.  These  are  deciduous  conifers  with  the  needles  in  clusters 
of  sixteen  or  more.  Where  these  trees  stand  thickly,  few  plants 
grow  under  them,  except  the  sphagnum  which  usually  covers  the 
ground.  The  soil  is  wet,  peaty,  and  cold,  for  the  sunHght  does 
not  penetrate  the  dense  tamaracks  readily.  Soil  temperature 
remains  about  35°  F.  even  in  midsummer.  In  the  more  open 
parts  of  the  tamarack  bog,  in  addition  to  the  herbaceous  plants 
of  the  cassandra  zone  which  invade  it  to  some  extent,  there  are 
found  the  rush  aster  (Fig.  243),  swamp  rose,  Rosa  virginiana 
with  its  stout  hooked  prickles,  red-osier  dogwood,  poison  sumac, 
(Fig.  107)  and  several  ferns,  the  crested  shield-fern  (Fig.  244), 
royal  (Fig.  203),  and  cinnamon  ferns  (Fig.  205). 

Shoreward  from  the  tamarack  zone  there  occurs  a  transition 
zone  that  varies  according  to  the  environment.  One  may  pass 
from  a  t^'pical  black  oak  dune  association  to  the  tamarack  bog 
society  in  a  dozen  steps,  or  the  bog  may  gradually  change  to  an 
interdunal  swale  of  one  of  the  preceding  types.  The  transition 
may  be  from  an  oak-hickory  forest  in  moraine  country  through 


INTERDUNAL  PONDS  AND  TAMARACK  SWAMPS      201 

a  willow  marginal  zone  occupied  by  the  typical  plants  of  the 
usual  low,  wet  area. 

One  must  expect  to  encounter  many  variations  from  the 
typical  arrangement  outlined  above.  The  pond  may  have 
disappeared  entirely  as  the  floating  sedges  have  overgrown  it. 
The  sedge  zone  may  have  disappeared  and  the  sphagnum  bog 
may  occupy  the  whole  depression,  either  with  or  without  the 
tamarack  border.  The  association  may  be  in  a  still  later  stage 
in  which  the  tamaracks  only  are  present,  the  pond  having  filled, 
the  floating  sedge  zone  having  been  displaced  by  the  sphagnum- 
cassandra  association,  and  this  in  turn  driven  out  by  the  advance 
of  the  tamaracks.  This  tamarack  association  may  be  gradually 
disappearing  as  plant  debris  accumulates,  transforming  the  bog 
into  a  drier  area  with  abundant  humus  in  which  the  plants  of 
the  surrounding  highland  may  establish  themselves. 

Most  of  the  animals  of  the  tamarack  bog  are  not  peculiar 
to  it  but  are  found  in  other  marshes  or  swamps.  In  the  water 
held  by  the  leaves  of  the  pitcher  plant  there  breeds  a  species  of 
mosquito  that  is  subarctic.  Certain  orthoptera  are  the  most 
characteristic  animals  of  the  sphagnum  bog  and  its  borders — the 
short-winged  brown  locust,  Stenohothrus  curtipemiis,  the  striped 
locust,  Mecostethus  lineatus,  the  northern  locust,  Melanoplus 
extremis,  the  marsh  ground  cricket,  Nemohius  palnstris,  and  the 
small  brown  cricket,  Anoxipha  exigua.  The  bog  tiger  beetle 
(p.  145)  is  also  distinctive. 


CHAPTER   X 

THE  cli:max  forest  and  its  predecessor,  the 

OAK-HICKORY  TYPE 

» 

HE  succession  of  stages  traced  in  the 
preceding  chapter  lead  on  to  the  chmax 
forest.  On  the  dunes  cottonwoods  and 
their  confreres  are  replaced  by  the  pine 
association.  This  is  in  turn  invaded 
and  ultimately  displaced  by  the  black 
oak  society.  After  many  generations 
of  accumulated  forest  debris,  the  soil 
becomes  sufficiently  rich  in  vegetable  mold  under  such  trees  to 
support  red  oaks,  then  white  oaks,  and  the  mixed  oak  succession 
follows  with  its  associated  shrubs  and  herbs.  Then  hickories 
appear  with  the  oak,  and  finally  under  most  conditions  maples 
and  beeches  displace  all  other  trees.  The  interdunal  pond  and 
the  filling  lake,  if  they  lead  on  to  a  forest  at  all,  go  through  a 
similar  succession  and  end  in  the  same  climax  forest,  except 
possibly  in  the  case  of  the  sphagnum  bog. 

Probably  not  one  but  many  factors  are  involved  in  this  suc- 
cession. The  increasing  quantity  of  decomposing  vegetable 
matter  in  the  soil  not  only  supplies  more  and  more  plant  food  but 
it  also  increases  very  greatly  the  power  of  the  soil  to  retain  mois- 
ture. The  numerous  penetrating  rootlets  of  the  dense  forest 
growth,  the  burrows  of  earthworms  and  other  animals  not  found 
in  the  earlier  stages  increase  the  porosity  of  the  soil.  Increasing 
shade  prevents  rapid  evaporation,  maintains  a  lower  temperature 
by  shutting  out  the  sun 's  rays,  reduces  wind  action,  and  lessens 
very  greatly  the  light  intensity.  In  the  beech-maple  forest 
the  photographic  exposure  meter  indicates  a  light  intensity  of 
only  one-tenth  to  one-twentieth  that  of  the  surrounding  open 


202 


rHE  CLIMAX  FOREST  AND  ITS  PREDECESSOR 


203 


country.     The  plants  and  animals  of  the  forest  floor  are  there- 
fore shade-loving  and  moisture-loving  forms. 

The  maple-beech  forest  is  the  last  in  the  succession  because 
in  the  dense  shade  under  these  trees  few  seedlings  other  than 
beech  and  maple  can  survive;  the  young  of  the  other  trees 
demand  more  light.  This  is  probably  only  one  of  several  factors 
important  in  the  elimination  of  other  seedhngs.  As  the  pine 
forest  grows  old  and  dense,  black  oak  seedlings  appear,  and  these 
trees  gradually  overtop  the  pines,  the  latter  dying  in  the  struggle 


Figs.  245-247:  Fig.  245. — Leaf  and  flower  of  tulip  tree,  Lirodendron  Tidipifcra; 
Fig.  246. — Leaf  and  nut  of  white  walnut,  Jiiglans  cinerea;  Fig.  247. — Leaf  and  nut 
of  black  walnut,  /.  nigra. 

for  existence.  So  in  the  black  oak  forest  seedlings  of  red  and 
white  oak  appear,  and  when  mature  they  shut  out  the  black  oak, 
but  the  beech-maple  forest  has  only  beech  and  maple  seedlings 
together  with  a  few  other  trees  that  can  stand  the  same  con- 
ditions. There  will  be  an  occasional  tulip  tree  (Fig.  245),  black 
and  white  walnuts  (Figs.  246,  247),  black  cherry  (Fig.  248), 
hackberry  (Fig.  249),  with  some  elms  (Fig.  250),  and  sycamore 
(Fig.  251)  in  the  lower  portions. 

The  tulip  tree  (Fig.  245)  is  recognized  by  its  large  leaf,  shaped 
something  like  a  maple  leaf  with  the  lip  cut  square  off.     The 


204       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


•  s^ 


H- 


;'f^jd 


bark  of  the  walnut  has  high 
ridges  inclosing  diamond- 
shaped  areas.  The  pith  of 
the  twig  is  divided  into 
numerous  compartments  by 
cross-partitions.  The  bark  of 
the  black  cherry  is  broken 
into  irregular  polygonal  areas 
by  numerous  cracks  and  so 
has  something  of  the  appear- 
ance of  alHga tor-skin  leather; 
the  buds  and  twigs  are  bitter, 
tasting  much  hke  cherry  pits. 
The  bark  of  the  hackberry  has 
numerous  high,  corky,  verti- 
cal ridges  on  it,  while  the  bark  of  the  sycamore  scales  off  in  flakes, 
showing  light  patches  through  the  otherwise  greenish  brown  bark. 


Fig.  248. — Trunk  of  the  black  cherry, 
Prunus  serotina. 


Fig.  249. — Hackberry  trunk,  Celtis  occidentalis,  and  trunk  of  beech  (at  right) 


THE  CLIMAX  FOREST  AND  ITS  PREDECESSOR 


205 


The  climax  forest  is  distinctly  stratified  (Fig.  252).  Beeches 
(Fig.  249)  and  hard  maples  (Fig.  253)  rear  their  crowns  in  the 
intense  sunlight.  In  such 
a  superb  example  of  the 
climax  forest  as  is  found 
in  Warren's  Woods  near 
Three  Oaks,  Michigan,  a 
forest  preserved  for  all 
time  to  nature-lovers  by 
the  munificence  of  its 
owner,  the  late  E.  K.  War- 
ren, the  trees  rear  unrivaled 
columns,  75  feet  or  more, 
without  a  branch.  The 
Gothic  aisles  of  this  vast 
temple  are  ornamented 
with  trees  of  less  stature 
such  as  pawpaw,  hop  horn- 
beam, water  beech,  flower- 
ing dogwood,  redbud, 
Juneberry,  chokecherry 
(Fig.  116)  whose  tops  form 


Fig.  250. — American  elm,  Ulmus  americana 


a  second  stratum.  Then  comes  the  tall 
shrub  stratum  with  witch-hazel,  spice- 
bush,  high  bush  cranberry,  maple-leaved 
viburnum,  nannyberry,  wahoo,  black 
currants,  gooseberry,  leatherwood,  elder- 
berry. Beneath  these  is  a  lower  stratum 
of  low  shrubs,  herbs,  and  ferns.  Among 
the  low  shrubs  are  strawberry  bush, 
pigeon  berry  (Fig.  265),  sliinleaf  (Fig.  93), 
wintergreen  (Fig.  94). 

The  pawpaw  (Fig.  256)  has  a  trunk 
Fig.  251.— Leaf  and  fruit   from   5   to    lo  inches  in  thickness  with 

of  sycamore,  Plat  anus  occi-    j     1    i  ^i.  t,      1        ^i      i 

dentdis  dark  brown  smooth  bark;    the  leaves  are 


2o6       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

lance-shaped  with  the  broad  end  toward  the  apex.     The  flower 
is  quite  conspicuous,  an  inch  or  two  across,  dull  purple,  with 


Fig.  252. — Climax  beech-maple  forest  showing  stratification 

the  parts  in  threes.  The  hop  hornbeam  and  water  beech  have 
leaves  much  like  elm  leaves  in  general  form.  The  former 
(Fig.  257)  has  fruits  somewhat  similar  to 
hops.  The  bark  of  the  tree  is  narrowly 
ridged  and  shreds  off  in  narrow  strips. 
The  latter  (Fig.  137)  has  a  smooth  trunk 
that  is  fluted  hke  a  Corinthian  column. 
Witchhazel  (Fig.  255)  can  usually  be  recog- 


nized by  its  fruits  that  remain  on  the  shrub 
nearly  the  year  around.  The  dogwood 
(Fig.  254)  is  a  small  tree  conspicuous  when 
in  bloom,  for  the  blossom  cluster  is  sub- 
tended by  four  conspicuous  white  bracts. 
The  redbud  (Fig.  2^8)  is  also  a  low  tree.  ,    /*^*  ^  ^f  v  ^l    "^^P  ^ 

^      °       ^    ^  leaf  and   fruit,   Acer  sac- 

Clusters  of  red  pea-shaped  blossoms  come  chamm 


THE  CLIMAX  FOREST  AND  ITS  PREDECESSOR 


207 


in  spring  before  the  leaves.     These  blossoms  appear  on  short 

branches  that  come  out  from  the  main  trunk  and  main  branches. 

Even  when  not  in 

blossom  the  tree  may 

be  recognized  by  the 

presence   of   these 

short,  stubby,  flower- 
ing branches. 

The  maple-leaved 

viburnum   is    similar 

to  the  high  bush  cran- 
berry (Fig.  259)  which 

is  also  a  viburnum. 

It  is  a  lower  shrub, 

3-5   feet  high,  with 

maple-like  leaves  that 

are  downy  below  and 

fruits  that  are  at  first 

red,    then   purple. 

The  nannyberry 

(Fig.  260),   also   a 

viburnum,  has  upper 

leaves  that  are  taper-pointed  and  the  leaf  stems  are  winged. 

The  fruit  is  black.      Spicebush  (Fig.  298)  is  recognized  readily 

by  the  spicy  odor  of  the  crushed  leaves  and  twigs.     The  high 

bush  cranberry  is  a  fairly  tall 
shrub  or  low  tree  with  oval, 
finely  toothed  leaves.  The 
flower  cluster  of  small  white 
blossoms  is  large,  and  the  red 
fruits  conspicuous.  The  con- 
tained seed  is  flat.  The  wahoo 
(Fig.  261)  is  generally  recog- 

'fig.  255.-Twig  of  witch-hazel,  i7a;;;a-  "^^^^  ^y  the  four  corky  ridges 
melis  virginiana.  that  run  longitudinally  on 


Fig.  254. — Flowering  dogwood,  leaf  and  blossom, 
Cornus  florida. 


2'56 


2.5^ 


257 


2,6a 


258 


262 


263 


Figs.  256-264:  Fig.  256. — Pawpaw,  Ashnina  triloba;  Fig.  257. — Hop  horn- 
beam, Ostrya  virginiana;  Fig.  258. — Redbud,  Ccrcis  canadensis;  Fig.  25Q. — High 
bush  cranberry,  Viburnum  opidus;  Fig.  260. — Nannyberry,  V.lentago;  Fig.  261. — 
Wahoo  or  burning  bush,  Evonymns  atropurpureus;  Fig.  262. — Elderberry,  Sam- 
bucus  canadensis;  Fig.  263. — Strawberry  bush,  Evonymns  atnericana;  Fig.  264. — 
Jack-in-the-pulpit,  Arisaema  triphyllum;  the  larger  figure  shows  the  top  of  the 
"pulpit"  thrown  back. 


THE  CLIMAX  FOREST  AND  ITS  PREDECESSOR         209 


each  twig,  giving  the  twig  a  square  cross-section.  Leatherwood 
is  low,  not  over  7  feet  high,  with  very  soft,  white  wood  and  very 
tough,  fibrous  bark.  The  branchlets  are  jointed,  and  the  leaves 
are  very  short-petioled.  Elderberry  (Fig.  262)  is  readily  recog- 
nized by  the  very  large  amount  of  pith  in  the  stems.  The  wood 
layer  is  relatively  thin.  Strawberry  bush  (Fig.  263)  is  a  low 
shrub  with  more  or  less  of  a  creeping  habit.  The  leaves  are 
almost  without  stalks,  lance-shaped,  and  finely  toothed. 

On  the  ground  of  such  a  forest  there  are  a  large  number  of 
plants  (Fig.  55)  that  spring  up  quickly  in  the  spring  before  the 
trees  are  in  leaf,  blos- 
som, and  mature  their 
fruit  before  they  are 
so  densely  shaded  as 
to  preclude  their  in- 
tense activity.  The 
spring  beauty,  spring 
cress,  toothwort,  hepa- 
tica  (Fig.  139),  blood- 
root,  red  and  white 
trillium,  dog-tooth 
violet,  jack-in-the- 
pulpit  (Fig.  264), green 
dragon  (Fig.  266),  Dutchman's  breeches,  wild  ginger,  all  belong 
to  this  group.  This  vernal  flora  consists  of  plants  in  whose 
underground  stems  or  succulent  roots  there  is  stored  abundant 
food  for  this  burst  of  speed  in  the  accompKshment  of  their  life- 
cycle.  In  many  cases,  too,  their  leaves  and  flower  buds  are 
warmly  clothed  in  hair,  and  not  a  few  have  leaves  that  cuddle 
close  to  the  warm  earth  in  dense  clusters. 

Later  the  ground  is  pre-empted  by  plants  that  are  better 
able  to  endure  the  shade  and  that  take  more  time  to  blossom 
and  mature  their  fruit.  Such  are  the  long-spur  (Fig.  143)  and 
Canadian  violets  (Fig.  142),  wood  violet,  the  latter  with  a  pal- 
mately  five-  to  nine-lobed  hairy  leaf,  wood  phlox,  the  columbine 


Fig.  265. — Pigeon  berry  or  dwarf  cornel,  Cornus 
canadensis. 


210       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


(Fig.  122),  red  and  white  baneberry,  Solomon's  seal,  waterleaf, 
sweet  cicely,  clearweed  (Pilea  pumila) ,  bedstraw,  ginseng,  touch- 
me-not.  Certain  kinds  of  ferns  are  very  characteristic  of  such 
woods,  and  the  many  sorts  that  grow  are  here  noted  for  their 


Figs.  266-271:  Fig.  266. — Green  dragon,  .4;- /^acwa  dracontium;  Fig.  267. — 
Baneberry,  Actaea  alba;  Fig.  268. — Waterleaf,  Hydrophyllum  virginianum;  Fig. 
269. — Sweet  cicely,  Osmorhiza  Claytoni;  Fig.  270. — Clearweed,  Pilea  pumila 
Fig.  271. — Bedstraw,  Galium  aparine. 

luxuriance.  The  beech  fern  (Fig.  274),  maidenhair  (Fig.  275), 
wood  spleen  wort  (Fig.  276),  pale  wood  fern  (Fig.  277),  Christ- 
mas fern  (Fig.  278),  lady  fern  (Fig.  279),  margined  fern  (Fig.  280), 
florists'  fern  (Fig.  281),  and  ostrich  fern  (Fig.  282)  are  among  the 


THE  CLIMAX  FOREST  AND  ITS  PREDECESSOR 


211 


sorts  to  be  found,  some  abundantly,  others  only  in  favorite  spots. 
In  ravines  and  lower  areas  the  cinnamon  fern,  Clayton's  fern, 
and  sensitive  fern  are  to  be  noted,  while  the  brake  (Fig.  283)  is 
common  on  borders  and  open  spots.     Many  mosses  grow  on  the 


Fig.  272. — Ginseng,  Panax  trijolium 

decaying  logs  and  on  the  moist  ground;   lichens  are  plentiful 
and  fungi  particularly  abundant. 

Baneberries  (Fig.  267),  both  white  and  red,  are  low  shrubs 
with  a  leaf  having  a  three-parted  stalk,  each  division  bearing 
three  to  five  leaflets.     In  water  leaf  (Fig.  268)  the  green  leaves 


212       A  NATURALIST  IN  THE  GREAT  LAKES  REGION     . 


are  mottled  with  pale  areas  looking  as  if  the  darker  color  had 
been  washed  out  by  sprinkling  water  on  the  leaf.  The  leaves 
are  quite  large,  deeply  lobed,  and  hairy.  Sweet  cicely  (Fig.  269) 
gives  the  odor  or  taste  of  licorice  when  the  foliage  is  crushed. 
Clearweed  (Fig.  270)  has  a  semi-transparent  stem.  The  leaves 
are  egg  shaped  and  bear  large  coarse  teeth.  The  flower  clusters 
are  in  the  axils  of  the  leaves.  The  plant  looks  like  a  nettle,  but 
does  not  have  stinging  hairs.     Bedstraw  (Fig.   271)   is  a   low 


Fig.  273. — Touch-me-not  or  wild  balsam,  Impaticns  pallida.  Blossoms  at 
right,  pod  at  left;  inset,  pods  after  discharge  of  seeds. 

trailing  herb  whose  foHage  is  harsh.  The  stems  are  covered 
with  points  that  make  them  very  rough.  Ginseng  (Fig.  272) 
when  in  blossom  is  readily  recognized  by  the  small  ball  of  white 
flowers.  Touch-me-not  (Fig.  273)  only  occurs  in  the  moist 
places.  The  stem  is  translucent ;  the  flowers  are  yellow,  mottled 
with  dark  spots.  The  seed  pod,  when  ripe,  explodes  on  touch, 
scattering  seeds  to  some  distance. 

Animal  life  is  as  abundant  and  varied  as  the  plant  life. 
Earthworms  are  abundant  in  the  soil.  Here,  too,  are  some  insect 
nymphs  like  that  of  the  cicada.     Some  rodents  are  present  as 


<k^?.iJ^ 


Figs.  274-282:  Fig.  274. — Beech  fern,  Phegopteris  poly podi aides;    Fig.  275. — 
Maiden-hair  iern,  Adianttim  pedatmn,  portion  of  frond;    Fig.  276. — Wood  spleen- 
wort,  yl5/>/e?jr;/wafro5//r/w/^c5;  Fig.  277. — Pale  wood  fern,  Aspidiuni  novaboracense; 
Fig.    278. — Christmas   fern,   Polystichium   acroslichoides;    Fig.    279. — Lady   fern, 
Asplenium  Filix-femina;  Fig.  280. — Margined  fern,  Asp/'dium  marginale;  Fig.  281 — 
Florists'  fern,  .4.  spimdoswn;  Fig.  282. — Ostrich  fern,  Onoclea  slrulhtopteris. 


214       ^  NATURALIST  IN  THE  GREAT  LAKES  REGION 


characteristic  inhabitants,  such  as  the  common  mole  (Fig.  286) ; 
the  common  or  long-tailed  shrew,  similar  to  the  short-tailed 
(Fig.  425),  but  the  former  is  only  4  inches  long,  the  tail  making 
1.5  inches  of  that  length;  the  latter  is  5  inches  long  and  the  tail 
is  only  i  inch  or  less;  and  the  white-footed  deer  mouse  (Fig.  287). 
Under  and  in  the  old  logs  in  various  stages  of  decay  are  found  a 
host  of  snails.  Indeed,  this  moist  forest  is  the  favorite  haunt 
of  the  land  snails  and  slugs,  Polygyra  albolabris,  fraiidulenta, 

Jiirsuta,  inUecta,  mono- 
don,  oppressa,  palliata. 
are  abundant  as  are  also 
Pyramidula  alternata, 
perspectiva,  and  solitaria, 
Omphalina  fuliginosa 
and  friabilis,  Zonitoidcs 
arhoreus.  Circinaria 
conCava  is  common,  a 
carnivorous  form  that 
feeds  on  other  land  snails 
(Figs.  284,  285).  In 
moist  weather  all  these 
kinds  may  be  found 
traveling  over  the  leaves 
upon  the  ground,  old 
logs,  shrubs,  and  tree 
trunks.  In  drier  weather  they  are  in  hiding  under  logs  and 
stumps.  The  Polygyras  are  all  land  snails  distinguished  by  the 
fact  that  the  edge  of  the  opening  of  the  shell  is  reflected  in  a 
broad  lip.  P.  fraudulenta  and  P.  inflecta  have  two  projections 
called  ''teeth"  on  the  Hp  of  the  opening,  one  on  the  body  wall 
(parietal  tooth).  The  former  has  an  open  umbiKcus  at  the 
base  of  the  spire,  the  latter  has  none.  P.  monodon,  P.  hirsiita, 
and  P.  fraterna  are  small,  one-half  inch  or  less  in  diameter.  The 
lip  is  notched  in  hirsuta,  and  the  shell  is  covered  with  short  dense 
hair.     P.  fraterna  is  similarly  hairy,  but  the  lip  is  not  notched. 


■ 

m 

K?-;^    if'^-^^m 

R 

IflHj^^^^^^^H 

Wmt%.  a^«* -ali&  ; 

HJKi 

fea.-#^*^ 

^Wt..-..^-..-..|| 

Fig.  283. — Bracken  fern,  Pteris  aquilira 


THE  CLIMAX  FOREST  AND  ITS  PREDECESSOR 


215 


Its  shell  is  narrowly  umbilicate.   P.  monodon  is  not  hairy,  the  lip  is 
not  notched,  and  it  is  widely  umbilicate.     The  following  are  much 


^^ 


a 


d 


f 


Fig,  284. — Various  species  of  Polygyra,  common  land  snails,  life  size: 
a,  Polygyra  alholabris,  the  white-lipped  snail  (note  covered  umbilicus) ;  b,  P.  hirsuta, 
the.  hairy  snail  (note  notch  in  lip);  c,  P.  midtilmeata,  the  many-banded  snail; 
d,  P.  palliata;  e,  P.  pennsylvanica;  f,  P.  profunda  (note  wide  open  umbilicus); 
g,  P.  thyroides;   h,  P.  Irldentata,  the  three-toothed  snail. 


2i6       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


m 


Fig.  285. — Land  snails:  a,  Circinaria  concava;  b,  Hclicodiscus  parallel  us; 
c,  Omphalina  fidiginosa;  d,  Polygyra  tridcntata;  e,  Zonitoidcs  arbor cus;  f,  Polygyra 
monodon;  g,  Pyramidula  altcrnata;  h,  Philomycus  carolinensis  (a  slug) ;  i,  Pyrami- 
dula  solitaria;  j,  P.  perspectiva;  k,  Succinea  avara;  I,  S.  ovalis;  m,  S.  rctusa; 
n,  Cochlicopa  lubrica;  0,  Bifidaria  armijera;  p,  Vertigo  ovata;  the  last  three  much 
enlarged, 


THE  CLIMAX  FOREST  AND  ITS  PREDECESSOR 


217 


larger  shells.  P.  muUilineata  and  P.  profunda  are  marked  with 
revolving  brown  bands  and  are  the  only  ones  so  marked:  the 
former  has  no  umbilicus;  the  latter,  a  very  wide  one.  P.  albo- 
lahris  has  the  umbilicus  completely  covered,  P.  pennsyhanica, 


Fig.  286  Fig.  287 

Figs.  286,  287:  Fig.  286. — Under  side  of  head  end  of  common  mole,  Scalopus 
aqiialicus;  Fig.  287. — White-footed  deer  mouse,  Pcromycus  leucopus,  and  imprint 
of  fore  and  hind  foot,  reduced  one-half. 

nearly  covered,  P.  thyroides  about  half-covered.  The  latter  is 
distinctly  striate  with  line  ridges.  P.  clausa  is  similar  but 
unstriate,   and   the   shell  is  high   as   compared  with   that   of 

P.  thyroides. 

The  Pyramidulas  do  not 
have  the  reflected  lip. 
Their  shells  are  quite  flat 
and  coarsely  striate.  P.  per- 
spectiva  and  striatella  are 
small.  The  former,  .5  inch 
in  diameter,  reddish  in 
color,  has  six  and  one-half 

Fig.  288.— The  common  slug, /lgno/ma.i;      whorls.      The  latter,    .25 

campestris.  jn^}^  [^i  diameter,  is  brown 

in  color  and  has  only  four  whorls.  P.  solitaria  has  three 
spiral  brown  bands,  while  P.  alternata  is  marked  with  alternate 
patches  of  dark  and  Hght.  The  Omphalinas  have  paper-thin 
poKshed  shells.  O .  fuliginosa  is  mahogany  brown  with  a  pearly 
aperture.  O.  friahilis  is  similar,  but  the  shell  is  still  thinner. 
Zonitoides  arboreus  is  small,  only  .12  inch  in  diameter.    The  shell 


2i8        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

is  amber  if  empty,  dark  brown  when  the  animal  is  in  it.  Cir- 
cinaria  concava  is  .5  inch  or  more  in  diameter,  green  horn-color 
outside  and  red-brown  within  the  aperture. 

The  great  slug,  Philomycus  carolinensis  (Fig.  285),  and  the 
smaller  slugs,  Agriolhnax  campestris  (Fig.  288)  and  Pallifera 
dorsalis,  are  found  in  similar  situations.  Not  infrequently  under 
strips  of  bark  one  finds  clusters  of  the  eggs  of  slugs  or  snails  like 


Fig.  289. — The  large  millipede,  Spiroboliis  margiiiatus 

heaps  of  small  pearls.  Philojnycus  is  yellow  white,  spotted  with 
brown  or  black.  The  other  two  are  ashy  in  color.  Pallifera  has 
a  dark  line  down  the  back  and  is  less  than  an  inch  long.  Agrioli- 
max  is  larger  with  no  line  down  the  back.  Under  the  bark  of 
logs  in  midstages  of  decay  one  finds  also  several  centipedes  and 
millipedes.  The  big  round  Spiroboliis  marginatiis  (Fig.  289) — 
.5  inch  in  diameter  and  5  or  6  inches  long  when  full  grown — is 


Fig.  2go  Fig.  291 

Fig.    290,291:    Fig.    290. — Yellow-margined   centipede,   Fonlaria   corrugate; 
Fig.  291. — The  red  centipede,  Gcophilus  riibens. 

fairly  common.  Another,  F,ontaria  corrugate  (Fig.  290),  is  flat- 
tened somewhat  and  is  brown  in  color  with  yellow  margins. 
Lysiopetalum  lactarium,  a  centipede,  discharges  a  milky  fluid 
when  handled,  while  Geophilus  ruhens  (Fig.  291)  is  a  large  reddish 
fellow.  Sow  bugs  and  roaches  are  abundant  here,  too.  In  logs 
that  are  in  earlier  stages  of  decay  one  finds  numerous  boring 
beetles.     The  click  beetles  and  their  larvae,  the  wire  worms, 


THE  CLIMAX  FOREST  AND  ITS  PREDECESSOR 


219 


including  the  big  eyed  elater  (Fig.  292),  are  common  under 
the  bark,  as  are  some  ground  beetles  in  hiding  here.  The 
green-legged  locust  and  Blatchley's  locust  (Fig.  293)  are 
characteristic.  In  the  wood,  in  gal- 
leries which  they  excavate,  are  the 
larvae  of  wood  borers;  the  flatheads, 
larvae  of  metallic  wood  borers,  and 
the  fleshy  grubs  of  the  horned  Fas- 
salus  (Fig.  294).  Carpenter  ants  and 
carpenter  bees,  the  latter  small  but 
brilHantly  colored  in  metallic  blues 
and  greens,  are  to  be  found  in  the 
same  situation.  Several  species  of 
beetles  (Fig.  295)  are  found  in  the 
fungi  on  the  forest  floor  and  on  old 
logs.  Two  amphibians  are  charac- 
teristic here,  the  red-backed  sala- 
mander found  hiding  in  moist 
recesses  under  old  logs,  and  the  wood  frog,  Rana  sylvatica 
(Fig.  296).  The  latter  is  so  common,  hopping  on  the  forest 
floor,  and  so  characteristic  of  the  cHmax  forest  that  Shelford 
calls  this  beech-maple  society  the  wood  frog  association.     Tree 


Fig.    292. — The    eyed    elater, 
Alans  ociilatus,  and  its  larva. 


Fig.  293. — Blatchley's  locust,  Melanoplus  blakhlcyi 


frogs,  Hyla  versicolor  and  H.  pickeringii,  are  found  here  but  are 
also  abundant  in  earlier  forest  stages  (Figs.  173,  174). 

In  the  shrub  stratum  are  some  characteristic  insect  larvae  and 
some  spiders.  The  larva  of  Papilio  ajax  is  found  on  the  pawpaw, 
and  the  butterfly  wings  its  tantalizing  flight  through  the  forest 
and  about  its  margin  (Fig.  297).     The  green-clouded  swallowtail, 


2  20       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Papilio  troilus  (Fig.  298),  rears  its  young  on  the  spicebush. 
Epeira  gigas,  Neocosoma  arabesca  (Figs.  304,  305)  are  character- 
istic spiders  hanging  their  webs  on  the  taller  shrubs,  though 

they  are  even  more  abundant 
in  the  oak-hickory  associa- 
tion. 

This  forest  is  the  home  of 
many  birds.  The  ovenbird 
builds  its  overarched  nest  on 
the  ground.  The  wood  pewee 
calls  plaintively  from  the 
quiet  deeps  of  the  woods. 
The  evening  song  of  the  wood 
thrush  lends  charm  to  the 
quiet  hour.  Both  these  and 
the  red-eyed  vireo,  the  scarlet 
tanager,  and  the  great  crested 


Fig.  294. — The  horned  Passalus  and 
its  larva,  Passalus  cornuius. 


flycatcher  nest  in  the  shrubs  and  low  trees.  During  migration 
the  tree  tops  are  alive  with  warblers;  the  black  and  white  creep- 
ing and  the  yellow  warblers  remain  to  nest.     The  red-shouldered 


Fig.  29s 


Fig.  296 


Figs.  295,  296:    Fig.  295. — Fungus  beetles:  a,  Diaper  is  maculata;   b,  Pisenus 
humeralis;    c,  Bolctotherus  bifurcus;   Fig.  296. — The  wood  frog,  Rana  sylvatica. 

hawk,  together  with  some  other  hawks,  nest  early  in  the  taller 
trees.  At  dusk  the  call  of  the  little  screech  owl,  a  wavering 
minor  whistle,  and  the  hoot  of  the  great  horned  owl  are  heard. 
These  nest  in  February  in  the  hollows  of  the  trees. 


THE  CLIMAX  FOREST  AND  ITS  PREDECESSOR         221 


The  oak-hickory  forest,  with  scattered  individuals  of  black 
cherry,  walnut,  and  linden,  is  the  prevalent  type  on  the  moraines 
about  Chicago.  It 
also  is  stratified  as  is 
the  beech-maple 
forest,  though  the 
undergrowth  is  as  a, 
rule  not  as  tall  nor 
as  abundant.  Hazel, 
dogwood,  and  the 
wild  rose  are  among 
the  common  shrubs. 
The  spring  herbace- 
ous plants  are  simi- 

,  Fig.  297  Fig.  298 

lar  to   those  Ot    the          p^^^    ^^^^   ^^g.    -pj^    297.— Pawpaw    swallowtail, 

beech-maple  forest.  PapUio   ajax,    on    pawpaw;    Fig.    298.— Spicebush 

Goldenrods,  asters,  swallowtail,  P.  troilus,  on  spicebush. 

and  sunflowers  are  abundant  in  the  fall.     Ferns  are  at  times 
abundant,  but  only  a  few  of  the  ferns  found  in  the  beech-maple 

forest  are  present  in 
the  oak-hickory 
forest.  The  com- 
mon ones  are  cin- 
namon fern,  the 
interrupted  fern,  the 
sensitive  fern  in  the 
moist  areas,  and  the 
brake  in  open  spots. 
There  are  char- 
acteristic animals 
in  the  soil,  on  the 

Fig.  299. — Cicada,  Cicada  linnei,  and  nymph  of  a    ground     and   in    the 
cicada,  the  one  below  much  enlarged.     From  Lugger,    i..,  r     j 

^  ^^      htter  of   decaying 

leaves  close  to  the  ground.     There  are  specific  societies  on  the 
fungi   and   in   decaying  logs,   a  society  peculiar  to  the  forest 


2  22        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


undergrowth  of  shrubs  and  herbaceous  plants  and  a  distinct 
community  of  the  forest  crown. 

The  cicada  or  periodical  locust  (Fig.  299)  sings  its  strident 
drone  in  the  tree  tops,  though  most  of  its  hfe,  as  a  nymph,  is 
spent  in  the  soil  stratum  of  the  forest.  The  katydid,  Cyrtophil- 
liis  perspicillatus,  lives  its  entire  Kfe  from  egg  to  adult  in  the 
tree  tops.  The  tree  cricket  (Fig.  300)  is  common,  as  also  the 
walking-stick.     There  are  a  number  of  butterfles  and  moths 


d 


f 


g 


Fig.  300. — Tree  crickets  of  several  species:  a,  male,  b,  female  of  Occanthus 
fasciaius;  c,  Basal  joint  of  antennae  of  0.  fasciatus;  d,  0.  angustipennis;  e, 
0.  quadripunctatus;  f,  O.  latipennes;  g,  0.  nivens. 

whose  larvae  feed  upon  the  foliage.  Among  these  are  the  tiger, 
swallowtail  (cherry),  and  the  giant  swallowtail  (hop  tree),  the 
walnut  sphinx,  the  lunar  moth  (hickory,  w^alnut),  the  royal  moth 
(walnut),  imperial  moth  (many  trees),  Polyphemus  (many),  Pro- 
methea  (cherry),  yellow-gray  underwing  (hickory),  the  widow 
(hickory),  Cecropia  (many). 

Many  beetles  are  peculiar  to  the  forest  crown  such  as  the  oak 
twig  pruner  (Fig.  301),  the  hickory  girdler,  Oncideres  cingulatus, 
whose  larvae  develop  in  twigs  that  have  fallen  to  the  ground  after 
being  girdled  more  or  less  completely  by  the  adults  up  in  the 


THE  CLIMAX  FOREST  AND  ITS  PREDECESSOR        223 


trees.  Several  species  of  the  June  beetles  are  found  feeding  on 
the  leaves,  as  are  many  kinds  of  leaf  beetles  such  as  Tymnes 
tricolor,  T.  matasternalis,  Cha- 
lepus  nervosa,  C.  rubra  (Fig. 
302),  Xanthoma  lo-notata. 
These  are  small  beetles  .25 
inch  or  less  in  length.  Most  of 
the  leaf-eating  beetles  are 
small.  The  elm-leaf  beetle, 
Galetucella  luteola,  is  one  of 
the  most  familiar  of  the  leaf 
beetles  attacking  tree  foliage. 
Acorns  and  hickory  nuts  af- 
ford homes  and  food  for  the 
larvae  of  several  species  of  nut 
weevils  belonging  to  the  genus 
Balaninus  (Fig.  303)  and  later 
to  some  moth  larvae.  These 
tall  tree  tops  afford  good  nest- 
ing sites   to   the  red-headed 


Fig.    301. — Twig   pruner  of   oak, 
Elaphidion  villosum.     X3. 


woodpecker,  the  flicker,  and  the  larger  owls.    The  flying  squirrel, 
which  is  largely  nocturnal,  spends  its  life  in  the  trees. 

In    the    undergrowth    community   the 

spiders,  Epeira  gigas  (Fig.  304)  and  Neoco- 

soma  arahesca  (Fig.  305),  are  characteristic; 

their  webs  are  hung  on  the  taller  shrubs. 

The  jumping  spider,  Phidippus  audax  (Fig. 

306),  is  prevalent  in  shrubs,  on  tree  trunks, 


Fig.  302 


Figs.  302,  303:   Fig.  302. — A  leaf  beetle,  Chalepiis 
Fig.  303. — A  nut  borer,  genus  Balaninus.     Both  X6. 


Fig.  303 
rubra. 


After  Blatchle}^; 


224       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

and  fallen  logs.  Harvest  spiders  or  daddy  longlegs  are  abun- 
dant. Among  butterflies  the  wood  nymph  and  wood  satyr  are 
conspicuous  by  their  numbers.  The  forked-tail  and  round- 
winged  katydids  are  prevalent  (Fig.  322). 

The  ground  stratum  is  thickly  populated.  The  most  con- 
spicuous denizen  is  perhaps  the  green  tiger  beetle,  and  Shelford 
names  the  oak-hickory  association,  on  its  animal  side,  the  green 
tiger-beetle  association.  This  briUiant  tiger  is  only  one  of  several 
predatory  ground  beetles  common  on  the  forest  floor.  They 
are  about  the  same  as  found  in  the  wood  frog  association.  The 
commonest  inhabitants  of  the  leaf  litter  are  the  myriopods,  of 
which  various  species  of  ''thousand  legs"  (millipedes)  of  the 
genus  Polydesmiis  and  "hundred  legs"  (centipedes)  of  the  genus 
Lithohius  are  most  prevalent.  Thirty  or  forty  to  the  square 
yard  may  often  be  found  when  the  leaf  litter  is  carefully  looked 
over.  They  are  an  important  factor  in  the  transformation  of 
the  dead  leaves  to  leaf  mold.  Occasionally  one  finds  the  other 
myriopods  common  in  the  wood  frog  association  in  the  litter, 
but  they  are  more  often  under  loose  bark  on  old  logs;  they  are 
not  as  common  as  in  the  beech-maple  forest.  The  same  thing 
may  be  said  of  the  slugs  and  snails.  The  camel  cricket  (Fig.  307) 
and  the  short-winged  locust  are  fairly  abundant.  The  nymphs 
of  cicadas  are  common,  discovered  on  their  way  from  the  soil 
stratum,  where  they  live,  to  the  trees  where  they  emerge  as 
adults.  In  dry  seasons  the  nymphs  protect  themselves  from 
excessive  evaporation  by  building  a  closed  clay  chimney  up 
through  the  leaf  mold,  rising  sometimes  an  inch  or  two  above 
the  surface.  In  this  they  lie  until  they  are  ready  to  accomplish 
their  transformation  on  the  nearby  tree  trunk. 

There  is  a  constantly  changing  association  in  the  trunks  of 
the  trees,  beginning  with  the  standing  trunk  still  in  its  prime, 
continuing  through  the  dead  standing  timber,  the  fallen  log,  in 
its  various  stages  of  decay.  The  rustic  borer  (Fig.  308)  works 
in  the  wood  of  the  hickory,  oak,  and  beech  trunk  even  when 
the  tree  is  robust.     The  elm  borer  (Fig.  309)  begins  work  on 


THE  CLIMAX  FOREST  AND  ITS  PREDECESSOR         225 


304 


307 


305 


30  8 


310 


30  6 


309 


312 


Figs.  304-312:  Fig.  304. — Female  of  the  spider,  Epeira  gigas;  Fig.  305. — 
Female  of  the  spider,  Neocosoma  arabesca;  Fig.  306. — The  jumping  spider,  Phidip- 
pus  audax,  X3;  Fig.  307. — Female  of  camel  cricket,  Ccuihophilus  maadatus; 
Fig.  308. — Rustic  borer,  Xylotrcchus  colonus;  Fig.  309. — Elm  borer,  Saperda 
tridentata,  X2;  Fig.  310 — Graphisurns  fasciatus,  X3;  Fig.  311. — Calloides  nobilis, 
slightly  enlarjred;  Fig.  312. — Molorchus  bimaculatus. 


2  26       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


the  trunk  if  the  tree  is  at  all  weakened.  An  allied  species, 
Saperda  lateralis,  is  also  found  on  the  hickory,  and  S.  vestile  is 
very  destructive.  The  larva  of  the  goat  moth  also  attacks  lusty 
trees  and  bores  into  their  heartwood.  It  is  good  sized — some  two 
or  more  inches  long  when  full  grown.  Such  forms  open  the 
trees '  defenses  to  a  legion  of  other  insect  pests  that  are  seldom 
slow  to  follow  up  the  advantage  and  that  bore  into  the  wood 
or  undermine  the  bark.  Such  are  the  fiathead  apple-tree  borer 
(Fig.  313).     The  adult  beetle  of  the  last-named  species  has  been 

known  to  emerge  from  wood 
made  into  furniture  several 
years  after  the  manufacture 
of  the  article,  the  pupa  hav- 
ing lived  during  a  long 
period  of  imprisonment,  so 
it  is  claimed. 

When  the  tree  has  suc- 
cumbed and  stands  as  a  dead 
Fig.  313— Flathead  apple-tree   borer,  or  nearly  dead  tree,  the  oak 

Chrysobothris  femorata;  a,  larva;  b,  adult;  fg  attacked,  in  addition  tO 
c,  face  of  larva;  d,  pupa.     After  Chittenden.    ,i       r  •         1  i    r 

^  ^  the  loregomg,  by  such  lorms 

as  Graphisurus  fasciatus  (Fig.  310),  Calloides  nohilis  (Fig.  311), 
while  the  hickory  supports  even  a  larger  beetle  population, 
common  among  which  are  Liophus  alpha,  Stenosphenius  notatus, 
Motor chus  himaculatus  (Fig.  312).  The  decay  of  the  log  goes  on 
through  many  years,  and  the  population  changes  as  decomposi- 
tion progresses.  The  trunk  may  still  stand  or  it  may  be  lying 
on  the  ground  when  the  bark  loosens  and  the  underlying  sapwood 
begins  to  rot.  Under  such  conditions  one  finds  a  curious 
assemblage  of  animals  representative  of  many  phyla.  The  slugs 
already  mentioned  in  the  beech  log  are  present,  though  not  as 
commonly  as  in  the  more  mesophytic  wood  frog  association. 
They  are  usually  found  near  the  base  of  the  standing  stump. 
Snails  are  represented  by  Potygyra  atbolabris,  P.  thyroides,  and 
other  species  of  Potygyra  already  listed  in  the  beech-maple  forest. 


THE  CLIMAX  FOREST  AND  ITS  PREDECESSOR        227 


Pyramidula  alternata  is  common  as  are  also  P.  perspectiva, 
Omphalifia  fuliginosa,  Zonitoides  arboreus,  and  Circinaria  concava. 
Millipedes  and  centipedes  are  almost  invariably  present.  The 
carpenter  ant  is  beginning  to  work,  the  female  being  found  early 
in  the  spring,  starting  the  colonies  in  small  hollows  excavated 
in  the  decaying  wood.  The  paper  wasp  frequently  winters 
under  such  loose  bark.  Certain  spiders,  such  as  the  w^olf  spider 
and  the  grass  spider, 
winter  in  such  locali- 
ties and  deposit  their 
egg  sacks  here. 

When  the  bark 
becomes  quite  loose 
on  standing  timber, 
the  brown  bat  hangs 
up  under  its  protec- 
tion by  day.  But 
the  predatory  and 
wood-boring  beetles 
make  up  the  bulk  of 
the  population.  The 
heartwood  borer, 
Parandra  brunea 
(Fig.  314),  is  fre- 
quently present,  working  where  decay  is  just  beginning.  This  is 
a  shiny,  chestnut  brown  beetle  about  .75  of  an  inch  long  and  a 
third  as  wide.  The  nearly  cyhndrical  larva  is  i  inch  long,  and  is 
recognized  by  the  sharply  sloping  thorax  and  the  small  head. 
Eupsalis  minuta  is  quite  common  under  bark  of  oaks,  even  in  early 
stages  of  decay  (Fig.  315).  The  horned  passalus,  a  good-sized 
black  beetle  with  a  horn  on  the  thorax,  may  be  present,  though  it 
is  more  common  in  the  fallen  logs  w^hen  decay  has  progressed 
somewhat  more.  Its  very  large  white  four-legged  larva  is  not 
likely  to  be  mistaken  for  anything  else  (Fig.  294).  Click  beetles 
are  almost  always  present.     Xylopimis  saperdioides,  Nytrobatcs 


Fig.  314. — Heartwood  borer,  Parandra  brunea,  and 
a,  its  larva;  b,  side  view  of  head  end  (Bulletin  United 
States  Department  of  Entomology). 


2  28       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


pennsyhayiica  (Fig.  316),  Tenehrio  tenehrioides  (Fig.  317),  Uloma 
impressa,  Meracintha  contracta  are  all  beetles  more  than  half  an 
inch  long  that  are  common  in  such  situations.  All  belong  to 
the  family  of  darkling  beetles,  and  the  list  might  be  much 
extended. 

Then  as  decay  becomes  more  complete  other  forms  largely 
replace  those  listed  above,  although  some  of  these,  as  for  instance 
Passalus  cormitus,  remain  even  in  well-decayed  wood.  The 
rotten-log  caterpillar,  Scolesocampa,  also  is  found  from  early  to 
late  stages. 


Fig.  315  Fig.  316  Fig.  317 

Figs.  315-317:  Fig.  315 — Oak  horev,  Eupsalis  minuta.  After  Felt;  Fig. 316. — 
Beetle,  X yd obatcs  pennsylvanica;  Fig.  317. — Beetle,  Tenehrio  lenehrioides.    All  X2. 

The  transition  from  the  upland  forest  to  the  surrounding 
prairie  is  accomplished  through  a  characteristic  forest  margin 
association.  For  the  oak-hickory  forest  that  is  so  commonly 
the  climax  on  the  morainal  hills  in  the  immediate  vicinity  of 
Chicago  this  consists  of  the  wild  crab  often  draped  with  the  wild 
grape,  the  trembling  asp,  the  hawthorns,  an  occasional  wild 
plum,  the  smooth  and  staghorn  sumacs,  hazelnut,  nannyberry, 
and  other  viburnums,  and  not  uncommonly  some  of  the  dog- 
woods. The  spring  and  summer  herbaceous  plants  are  not 
materially  different  from  those  of  the  adjacent  forest.  The  May 
apple  may  make  a  goodly  showing,   the   Canada   and  spear 


THE  CLIMAX  FOREST  AND  ITS  PREDECESSOR 


229 


thistles  and  ground-cherry  may  be  particularly  abundant,  or  the 
milkweed  toss  its  balls  of  blossoms  in  profusion,  while  in  the 
autumn  goldenrods,  wild  sunflower,  and  asters  seem  to  run 
riot  here. 

The  cottontail  rabbit, 
gray  gopher  (Fig.  319), 
common  shrew,  jumping 
mouse  (Fig.  318),  chip- 
munk, and  woodchuck 
(Fig.  320)  are  the  common- 
est mammals  of  this  forest 
margin  associatipn.  Birds 
are  particularly  abundant, 
for  the  almost  impenetrable  growths  of  wild  crab  and  hawthorn 
make  safe  nesting  sites,  while  the  cover  is  good  for  ground  birds. 
Bobwhite,  chewink,  mourning  dove,  song  sparrow,  chipping 
sparrow,  goldfinch,  indigo  bunting,  catbird,  brown  thrasher, 
and  shrike  are  all  common  in  such  haunts.     Crabs  and  haws 


Fig.    318. — The   jumping    mouse,    Zapus 
hudsonius. 


Fig.  319. — Gray  gopher,  Citellus  Jranklini 

are  blossoming  in  the  spring  in  mid-May,  at  which  time 
the  warblers  and  vireos  are  passing  over  the  Chicago  region 
in  great  waves  of  migration.  They  are  then  attracted  to  the 
blossoming  trees  by  the  many  insects  that  feed  upon  the 
blossoms. 

Insect  life  is  at  all  times  abundant  in  this  marginal  association. 
The  herbaceous  plants  of  spring  and  midsummer  mentioned 
above  each  attract  a  goodly  number  of  characteristic  guests, 


230 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


especially  the  thistles  and  the  milkweed.     The  larva  of  the 
monarch  butterfly  is  often  found  on  the   latter,  and  the  red 


Fig.  320. — "Woodchuck,  Marmota  monax,  and  footprints 

beetle,  Tetraopes  tetraophthal- 
mus,  is  almost  always  present. 
IMonarch,  viceroy,  anglewings, 
fritillaries,  wood  nymphs,  the 
cosmopolitan  (Pyrameis  hun- 
ter a),  and  painted  lady  (P.  car- 
diii)  (Fig.  321)  are  common 
butterflies,  the  larvae  of  the  two 
Fig.  32i.-The    painted    lad.v,  ^^st  mentioned  feeding  on  the 

Pyrameis  cardiii.  thistle,      HostS    of    flicS,    waspS, 

and  bees  feed  on  the  blossoms,  especially  in  the  autumn  when 
goldenrods  and  asters  are  the  chief  floral  restaurants  still  open 
to  hungry  insects.     Several  orthoptera  are  characteristic,  among 


THE  CLIMAX  FOREST  AND  ITS  PREDECESSOR        231 


Fig.  322. — Round-winged  katydid, 
Amblycorypha  rotundifoUa;  b,  tip  of  o\-i- 
positor.     After  Blatchley. 


which  may  be  mentioned  the  tree  crickets,  Oecanthiis  angustipen- 
iiis,  O.  fasciatus,  and  O.  nivens  (Fig.  300) ,  and  the  round-winged 
and  oblong-winged  katydids  (Figs.  322,  323);  the  short-winged 
locust,  Melanoplus  scudderi,  the  sprinkled  locust,  Chloealtis  con- 
spersa  (Fig.  2)^2))  ^  'the  sworded 
grasshopper,  Xiphidium  ensi- 
ferum,  the  woodland  grass- 
hopper, Xiphidium  nemorale. 

The  tree  crickets  are  gauzy- 
winged,  pale  green  insects, 
whose  stridulations  make  much 
of  the  insect  music  of  late- 
summer  nights.  The  oft-repeated  buzzing  notes,  sounding  in 
unison,  with  regularity,  give  a  rhythmic  pulsing  volume  of 
sound  that  keeps  up  from  dusk  to  long  past  midnight.  The  short- 
winged  locust  is  nearly 
an  inch  long.  The  color 
is  reddish  brown;  the 
hind  tibiae  are  bright 
red.  The  wing  covers 
are  short,  about  as  long 
as  the  pronotum,  the 
wings  still  shorter. 
Grasshoppers  of  the 
genus  Xiphidium  are 
small,  but  have  a  long 
ovipositor.  The  top  of  the  head  projects  forward  as  a  rounded 
prominence.  The  two  species  mentioned  have  bodies  about 
one-half  inch  long  and  are  greenish  brown  in  color.  The 
ovipositor  of  the  sworded  grasshopper  is  as  long  as  the  body; 
that  of  the  woodland  grasshopper  is  shorter  and  curved. 


Fig.  323. — Oblong-winged  Katydid,  Ambly- 
corypha oblongifolia.     After  Blatchley. 


CHAPTER  XI 

LAKE  TO  FOREST  OR  PRAIRIE 

S  WAS  noted  in  discussing  the  inter- 
dunal  ponds  the  ultimate  fate  of  pond 
or  lake  is  to  be  filled  with  the  outwash 
of  soil  from  the  surrounding  hills  and 
the  accumulations  of  vegetable  debris. 
Such  a  filling  lake  may  give  rise  either 
to  (i)  a  forest,  as  shrubs  and  trees  es- 
tablish themselves  in  the  firm  soils  of 
its  rising  margin  and  push  their  way  farther  and  farther  out  as 
filling  proceeds,  or  (2)  to  prairie.  Indeed,  these  two  associations, 
the  wet  forest  and  the  low  prairie,  may  develop  at  different 
parts  of  the  same  filling  lake  as  is  seen,  for  instance,  at  Wolf 
Lake  near  Chicago. 

Beginning  with  the  open  water  and  running  shoreward,  the 
zones  in  the  filling  pond  that  lead  to  the  forests  might  be  named 
as  follows:  (i)  open  water  area,  or  from  the  animals  predomi- 
nating, the  Pleurocera  area;  (2)  zone  of  submerged  plants  or 
the  aquatic  insect  zone;  (3)  w^ater  lily  zone  or  painted  turtle 
zone;  (4)  the  rush  zone — the  marsh  wren  zone;  (5)  the  cat- tail 
zone — red- winged  blackbird  zone;  (6)  the  shrub  zone,  the  katy- 
did zone;    (7)  the  ash-elm  zone,  the  green  heron  zone. 

Out  in  the  open  water  where  the  bottom  is  sandy,  the  water 
shallow  and  largely  free  from  invading  plants,  caddis-fly  nymphs 
are  abundant,  crawling  over  the  bottom,  as  are  also  such  snails 
as  Pleurocera  and  Goniohasis,  while  Vivipara  contectoides  is  occa- 
sionally found  (Fig.  324).  All  three  of  these  are  operculate.  In 
Pleurocera  the  aperture  is  produced  into  a  canal.  P.  elevatum 
has  nine  to  ten  w^horls,  P.  subulare  twelve.  Goniohasis  livescens 
is  broadly  conical  and  the  aperture  is  rounded  in  front.    Vivipara 


232 


LAKE  TO  FOREST  OR  PRAIRIE 


233 


Fig.  324. — Water  snails  showing  generic  characters:  a,  Lymnaea  reflexa;  b, 
L.stagnalis;  c,  L.woodruffi,;  d,  Physa  heteroslropha;  f,  Ancyliis  fitscus,  side  view; 
g,  Amnicola  cincinnaticnsis;  i,  A.  emarginata;  j,  Valvala  tricar inata;  k,  Plauorbis 
trivolvic,  from  above;  /,  P.  trivolvis,  side  view;  m,  P.  campanulatns,  from  below; 
n,  P.  campanulatns,  side  view;  0,  P.  hicarinatus,  from  below;  />,  P.  bicarinalus, 
side  view;  q,  Vivipera  contectoides;  r,  operculum  of  V.  contccloidcs;  s,  V.  sub  pur- 
purea; t,  Campeloma  ponderosum;  u,  C.  integrum;  v,  C.  subsolidum;  w,  Pleuroccra 
elevatimi;  x,P.subtdare;  y,  Goniobasis  livesccns;  z,  Sphacrium  transversum  (a.  clam). 


234       ^  NATURALIST  IN  THE  GREAT  LAKES  REGION 


contectoides  is  a  large  thin  shell,  banded  or  otherwise  brightly 
colored.  Here  too  are  such  clams  as  Alasmodonta  marginata 
(Fig.  i8i)  and  Lampsilis  luteola  (Fig.  i8o).  Some  fairly  good- 
sized  fish  come  into  the  shallow  area  to  lay  their  eggs  in  the  sand 
of  the  bottom,  such  as  the  black  bass,  pumpkin  seed  (Fig.  i88), 
bluegill  (Fig.  187),  perch,  crappie  (Fig.  438).  The  fish  may 
often  be  seen,  on  careful  approach,  swimming  in  the  neighbor- 
hood of  the  nest,  especially  the  male  that  does  guard  duty  until 
the  young  are  hatched.  In  the  very  shallow  water  the  blob  or 
miller's  thumb,  one  of  the  sculpins  (Fig.  325);  the  blunt-nosed 
minnow  (Fig.  429),  straw-colored  minnow  (Fig.  436),  and  the 


**^       Q;^         r 


Fig.  325.— Blob,  miller's  thumb,  or  sculpin,  Cottiis  ictalops.     After  Forbes 

Johnny  darter  (Fig.  429)  are  found  and  probably  breed  here. 
The  crayfish,  Cambarus  virilis,  is  common,  hiding  under  stones 
and  logs. 

The  waters  of  the  lake  are  the  habitat  of  many  algae  that 
grow  in  profusion,  Cladophora,  Spirogyra,  Oedigonuim,  Hydrodic- 
ton,  etc.  They  usually  go  under  the  common  names  of  pond 
scums  or  water  silk.  Nearer  shore  there  is  an  abundant  floating 
vegetation  consisting  of  such  Hepaticae  as  Riccia,  Ricciocarpiis 
and  flowering  plants  like  the  duckweeds.  Riccia  appears  like  a 
thick  green  leaf  (really  a  thallus)  about  as  large  as  your  finger 
nail.  There  are  short  rootlike  structures  (rhizoids)  given  off 
from  its  under  side.  It  floats  on  the  shallow  water  or  lies  on  the 
soft  mud.  Duckweed  is  also  a  floating  plant  with  one  or  two 
tiny  leaves  and,  for  a  short  time  in  spring,  a  tiny  blossom. 


LAKE  TO  FOREST  OR  PRAIRIE 


235 


3  26 


329 


332 


330' 


333 


328 


Figs.  326-334:  Fig.  326. — One  of  the  pond  weeds,  Polamogeton  nutans; 
Fig.  327. — A  club  rush,  Scirpus  atrovirens;  Fig.  328. — S.  Torreyi;  Fig.  329. — 
S.validus;  Fig.  330. — Xhogr\izh.,Juncus  hallicus;  Fig.  331. — J. tenuis;  Fig. 332. — 
/.  canadensis;   Fig.  2)ZZ- — J •  cffusus;   Fig.  334. — Spike  rush,  Eleocharis  acicidaris. 


236       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

It  bears  a  few,  short,  threadlike  roots.     The  surface  of  the  pond 
is  often  completely  covered  with  this  duckweed. 

Many  plants  root  in  the  soft  bottom  and  grow  more  or  less 
submerged;  such  are  pondweed,  Potamogeton  of  several  species, 
as  P.  natans,  P.  crispus,  P.  pectinatus,  P.  lucens,  P.  zosteri- 
folius;  water  milfoil,  Myriophyllum;  hornwort,  Ceratophyllmn; 
water  weed,  Elodea;  tape  grass,  Vallisneria;  bladderwort,  Utri- 
ciilaria;   water  buttercup.  Ranunculus  aqiiatilis  (Fig.  64). 


Fig.  335. — The  bulrush  zone,  GaHen  River,  New  Buffalo,  Michigan 

Pondweed  (Fig.  326)  roots  at  the  bottom  of  the  pond  and 
sends  up  its  leafy  stalk  to  the  surface.  Some  of  the  leaves  may 
lie  on  the  surface  of  the  water.  Such  are  usually  fairly  firm 
and  broad,  while  the  submerged  leaves  are  commonly  narrow, 
translucent,  and  fragile.  Potamogeton  natans  has  egg-shaped 
floating  leaves  i  inch  or  more  long  and  very  narrow,  submerged 
ones  less  than  .1  of  an  inch  wide.  P.  crispus  has  only  submerged 
leaves  which  are  lance-shaped  and  are  borne  on  short  stems. 
The  margins  of  the  leaves  are  finely  saw-toothed  and  crinkly. 


LAKE  TO  FOREST  OR  PRAIRIE 


237 


P.  pectinatus  is  entirely  below  water.  Its  leaves  are  long  and 
narrow  and  are  provided  at  the  base  with  stipules  which  unite 
with  the  base  of  the  leafstalk  to  ensheath  the  stem.  Tape  grass 
or  eel  grass  has  long,  ribbon-like,  narrow  leaves,  entirely  below 
water  or  at  times  with  the  tips  floating.  The  blossom  is  borne 
on  a  string-like  stalk  that  is  coiled  at  first  to  hold  the  bud  below 
the  surface  and  that  uncoils  and  lets  the  blossom  to  the  surface 
only  while  it  opens  long  enough  to  permit  of  fertilization. 


336 


337 


338 


Figs.  336-338:  Fig.  336. — Bur  reed,  Sparganium  eurycarpiim;  Fig.  337. — 
Arrowhead,  Sagittaria  latifolia;   Fig.  338. — AMld  rice,  Zizania  aquatica. 

Then  comes  the  water  lily  zone  with  water  shield,  Brassenia 
purpurea;  lotus,  Nelumho;  yellow  and  white  water  lilies. 

Shoreward  still  farther  comes  the  bulrush  zone  (Fig-.  335), 
with  Scirpiis  lacustris,  S.  validus,  S.  atrocinctus,  S.  americanus , 
S.  TorreyiyS.  atrovirens  (Fig.  327),  and  other  species;  rushes  of 
the  genus  Junctis  like  /.  halticus  littoralis;  spike  rushes  like 
Eleocharis  acicularis,  E.  palustris,  etc.  The  bulrushes  have,  as  a 
rule,  long,  tapering,  solid  round  leaves  sheathed  at  the  base. 
The  inconspicuous  perfect  flowers  are  borne  in  spikelets  that  are 
in  some  species  solitary,  in  others  clustered  near  the  end  of  the 
leaf.  Torrey's  rush  (Fig.  328)  and  the  American  rush  are  the  only 
common  ones  in  our  neighborhood  that  have  sharply  triangular 


238       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


m^B 


Fig.  339. — The  reed, 
Phragmites  commun is. 


stems.  The  scales  of  the  flower  cluster  in  the  former  are  reddish 
browTi;  in  the  latter,  yellow  brown.  Scirpus  validus  (Fig.  329), 
the  great  bulrush,  may  be  8  feet  high  and  proportionally  lusty. 

The  sheaths  at  the  bases  of  the  soft, 
light  green  leaves  are  soft  and  rather 
transparent.  In  Scirpus  atrocinctiis  the 
bases  of  the  bracts  that  are  below  the 
flower  cluster  are  black. 

In  the  bog  rushes  {J uncus)  the  flowers 
and  fruits  are  not  inclosed  in  huskhke 
scales  as  they  are  in  the  bulrushes.  The 
leaves  are  pithy  or  in  some  species 
hollow.  The  small  flowers  are  clustered 
but  not  in  spikes.  The  flower  cluster 
appears  to  be  on  the  side  of  the  stem 
rather  than  on  the  end  in  /.  halticus 
(Fig.  330).  The  plants  appear  in  the 
latter  species  in  rows  arising  from  the  un- 
derground stem.  There  are  many  other  species  such  as  /.  tenuis 
(Fig.  331),  J.  canadensis  (Fig.  332),  /.  efusus  (Fig.  2,2>3), 

Every  stalk  of  the  spike  rushes  ends  in  a 
spike  of  blossoms.  The  stalks  are  spongy 
inside.  Those  of  Eleocharis  acicularis  (Fig. 
334)  are  not  over  4  inches  in  height  (unless 
the  plant  is  growing  submerged) ,  and  hairlike, 
they  are  so  fine.  Eleocharis  palustris  is  similar 
but  stouter.  Its  stalks  are  cylindrical;  its 
fruits,  lenticular.  The  stalks  of  E.  acicularis 
are  more  or  less  four-angled,  and  the  fruits  are 
triangular  in  cross-section. 

Cat-tails  come  in  next,  the  common,  Typha  Fig.  '340'.— Sweet 
latifolia,  and  the  narrow-leaved,  T.  angustifolia.  ^^S'  Acorns  Calamus. 
Then  more  or  less  mixed  with  the  preceding  plants  come  a  num- 
ber of  marginal  plants:  bur  reed  (Fig.  336);  arrowheads,  Sagit- 
taria  variabilis  (Fig.  337),  and  S.  heterophyla;  pickerel  weed;  wild 


LAKE  TO  FOREST  OR  PRAIRIE 


239 


rice   (Fig.  338);    water-reed,   Phragmites  communis  (Fig.  339); 
sweet  flag  (Fig.  340). 

Along  the  margin  of  the  open  water  soft-shell,  musk  and 
geographic  turtles  are  to  be  expected.  The  first  is  easily  known 
by  its  leathery  rather 
than  bony  shell;  the 
second,  by  its  musky 
odor;  the  third,  by 
the  fine  lines  on  each 
bony  plate  of  the 
shell  that  give  an 
appearance  some- 
thing Uke  a  map. 
Farther  in  shore  in 
the  zone  of  submerged 
plants,  especially  in 
the  bays,  are  many 
adult  and  larval  in- 
sects that  may  be 
dredged  up  with  the 
plants.  The  top  min- 
now, Fundulus  dispar, 
is  common  (Fig.  434). 
Among  the  insects  are 
the  water  scorpion, 
giant  water  bug, 
water  boatman,  many 
diving  beetles  of  the 
families  Dytiscidae 
and  Hydrophylidae,  and  May-fly  nymphs.  Dragon  and  damsel- 
fly  nymphs  are  common,  and  the  molt  skins  of  the  latter  are 
commonly  found  on  the  rushes  and  cat-tails.  A  few  of  the 
more  frequent  dragon  flies  are  Anax  Junius,  Gomphus  spica- 
tus,  and  Libullula  pulchella.  These  insect  larvae  are  already 
famiKar  from  the  study  of  the  interdunal  ponds,  as  are  also  the 


Fig.  341. — The  painted  turtle 


240       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Fig.  342. — The  snapping  turtle 


snails,  clams,  and  small  crustaceans  found  abundantly  here.     In 

the  zone  of  submerged  plants  the  shrimp  Palaemonetes  paludo- 

sus  (Fig.  56)  is  common,  especially  in  the  cooler  waters.     Here 

also  one  finds  the  large 
gelatinous  masses  in- 
closing colonies  of  the 
polyzoan  Pectinella 
magnifica.  Here,  too, 
and  in  the  zone  of  the 
water  hlies,  the  painted 
turtle  (Fig.  341)  and 
the  snapper  (Fig»  342) 
are  usually  prevalent, 
and  such  frogs  as  the 
leopard,  pickerel,  green, 
and  bull. 
The  bullfrog  is  known  by  his  immense  eardrums,   much 

larger  than  his  eyes  (Fig.  343).     The  leopard  frog  is  yellow 

below;    above  he  is  mottled  with  black  blotches  on  a  yellow 

ground.     The  pickerel  frog  (Fig.  344)  is  light  brown,  marked 

above  with  three  rows  of 

squarish  blotches.     The 

green  frog  is  pale   green 

above,  marked  with  black 

blotches  and  is  also   pale 

green  below. 

The   bulrushes   afford 

nesting  sites  for  the  marsh 

wren,  both  long-  and  short-  Fig.  343.— Common  bullfrog,  Rana  cates- 

billed,    that    attach    their    bei^^^,^    male.     Bulletin    United  states    Fish 
,    ,     ,  J     j^     .^  i_        Commission. 

globular  nests  to  the  rushes 

(Fig.  345),  the  black  tern,  the  pied-billed  grebe  that  build 
floating  nests  sometimes  also  in  the  cat-tail  zone.  In  the  cat- 
tail zone  will  be  found  nesting  the  red-winged  and  yellow-headed 
blackbirds,  the  American  (Fig.  346)  and  least  bitterns.     The 


LAKE  TO  FOREST  OR  PRAIRIE 


241 


first  two  attach  their  nests  to  the  cat-tails  which  are  fastened 
together  in  a  loose  cluster  for  the  purpose.  In  these  two  zones 
one  finds  also  Virginia,  king,  and  sora  rails,  Florida  gallinules, 
coots,  herons,  and  sandpipers.  The  muskrat  builds  his  dome- 
shaped  house  of  the  cat-tails,  together  with  vegetable  debris 
raked  up  from  the  bottom. 

Pushing  out  from  shore  into  the  rush  and  cat-tail  zone  is 
the  shrub  zone.  The  buttonbush  or  elbowbush  is  the  pioneer. 
Back  of  it  comes  such  shrubs  as  prickly  ash,  an  aromatic  plant 
with  odd  pinnately  compound  leaves  and  prickers  on  the 
stems;  maple-leaved  viburnum,  red-osier  and  silky  dogwoods; 


Fig.  344. — The  pickerel  frog 

and  still  farther  back  comes  the  white  ash-elm  forest  association 
with  the  ash  the  predominant  tree.  Neither  the  ash-elm  forest 
nor  the  shrub  zone  at  its  margin  is  marked  by  many  strikingly 
distinctive  animals.  The  black-sided  grasshopper,  Xiphidiiim 
nigropleura,  is  common  on  the  shrubs  and  below  them.  The 
striped  shrub  crickets,  the  Texan  katydid  (Fig.  348),  the  oblong- 
winged  katydid,  and  the  forked-tail  katydid  (Fig.  347)  are  so 
prevalent  that  the  shrub  zone  may  justly  be  called  the  katydid 
zone.  At  times  the  larva  of  Papilio  cresplioiites  is  found  freely 
on  the  prickly  ash,  as  in  the  summer  of  192 1,  but  usually  the 
giant  swallowtail  is  rare  about  Chicago.  When  the  shrubs  are 
in  blossom  many  gnats  and  flies  are  hovering  about  them,  and 


242        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


then  the  dragon  flies  that  breed  in  the  adjacent  waters  are  busy 
hunting,  flying  with  quick,  darting  movements  along  the  open 
pathways. 

The  ash-elm  swamp  forest  is  inhabited  by  many  animals,  few 
of  which  are,  however,  peculiar  to  it.  Most  of  them  are  equally 
or  even  more  prevalent  in  the  elm-maple  forest  of  the  flood  plain. 

The  green  heron  often 
nests  in  the  ash  trees 
along  the  swamp  mar- 
gin and  may  be  taken 
as  the  typical  animal 
of  this  zone. 

Not  always  does 
the  filling  of  a  low  area 
in  the  Chicago  region 
ultimately  lead  to  a 
forest  area.  There  is 
another  association  of 
plant  and  animal 
forms  that  seems  to 
be  the  end  result 
of  such  a  process, 
namely,  the  prairie  as- 
sociation. Extensive 
prairie  areas  have  de- 
veloped   from    the 

Fig.  345. — Nest  of  marsh  wren,  woven  of  marsh     i^iarshes  that  formerlv 
grass.  ^ 

occupied,  and  m  part 

still  occupy,  the  beds  of  the  old  lakes  that  formed  back  of  the 

terminal  moraines,  such  as  the  Morris  Basin  and  the  Kankakee 

Basin.     They  have  developed  also  on  extensive  areas  of  sand 

that  outwashed  from  the  glacier  and  on  upland  regions  in  the 

moraines.     Possibly  the   prairie   finally   transforms   to   forest, 

but  if  so  the  prairie  stage  in  the  development  is  a  protracted 

one.     It  is  difficult  to  decide  just  what  it  is  that  determines 


LAKE  TO  FOREST  OR  PRAIRIE 


243 


that  one  lake  as  it  fills  shall  first  give  rise  to  marsh,  then  to 
swampy  forest,  later  to  the  succession  of  oak  and  hickory  forest, 
and  finally  to  the  climax 
forest,  while  another, 
after  the  marsh  condi- 
tion, proceeds  through 
wet  meadow  to  prairie. 
Possibly  differences  in 
depth  of  the  original 
lake  undergoing  filling 
and  consequent  differ- 
ences in  the  depth  of 
humus,  differences  in 
drainage,  in  soil  char- 
acter, as  well  as  other 
factors,  enter  into  the 
production  of  unlike 
end  results. 

Once  the  differences 
between  prairie  and 
forest  are  established, 
it  is  easy  to  see  enough 
contrasts  in  atmospheric  and  soil  temperatures,  in  water  content 
of  the  soil,  in  relative  percentage  or  saturation  of  the  atmos- 
phere, to  account  in  part,  perhaps 
entirely,  for  the  very  different 
plants  and  animals  in  the  two 
regions.  The  temperatures  in  the 
soil  and  among  the  vegetation  of 
the  forest  are  not  subject  to  such 
Figs.  347,  348:  Fig.  347  (top).—   extremes,  either  seasonal  or  di- 

Forked-tail    katydid,    Scudderia  ,  ^i  ... 

furcaia;  Fig.  348  (bottom) .-Texas   ^rnal,  as   on^  the   prairie.      The 
katydid,  S.  texensis.  temperature  in  the  forest  and  in 

its  soil  is  lower  in  summer  and  at  midday  than  on  the  prairie. 
The  cool  air  protected  in  summer  by  the  forest  trees  is  a  much 


Fig.  346. — American  bittern,  Botaurus  lenti- 
ginosus. 


244       ^  NATURALIST  IN  THE  GREAT  LAKES  REGION 


349 


'3  52 


3  50 


351 


(55  '^  ^^356  '  357 

Figs.  349-357:  Fig.  349. — Carex  conjiincta;  Fig.  350. — C.  cristata;  Fig.  351. — • 
C.  litpuliformis;  Fig.  352. — C.  stricta;  Fig.  353. — Slough  grass,  Spartina  Michaux- 
iana;    Fig.    354. — Blue-joint   grass,    Calamagrostis   canadensis;    Fig.   355. — Fow 
meadow  grass,   Glyceria   nervata;    Fig.   356. — Switch   grass,   Panicmn   virgatmn; 
Fig.  357. — Thin  grass,  Agrostis  perennans. 


LAKE  TO  FOREST  OR  PRAIRIE 


245 


deeper  layer  in  the  forest  than  in  the  corresponding  layer  in  the 
relatively  short  vegetation  of  the  prairie.  The  forest  atmosphere 
is  more  humid  than  that  of  the  prairie. 
Evaporation  is  relatively  greater  on  the 
prairie. 

Most  of  the  original  prairie  has  passed 
under  cultivation,  and  the  prairie  flora  and 
fauna  have  largely  been  obliterated.  Scat- 
tered remnants  of  it  persist,  a  few  plants 
and  the  associated  animals  surviving  in 
this  locality,  a  few  others  elsewhere.  But 
in  few  if  any  localities  is  the  old  wealth  of 
prairie  forms  to  be  encountered  in  any- 
thing like  its  early  luxuriance.  Probably 
along  the  rights  of  way  of  the  railroads  the  p^^  2>S^.-Andropogon 
prairie  forms  are  found  more  abundantly  furcatus. 


Fig.  359. — Luxuriant  grasses  of  wet  prairie 


246       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


than  anywhere  else.  There  are  stretches  where  the  traveler 
catches  glimpses  of  the  carpet  of  brilliant  and  varied  blossoms 
that  once  spread  far  and  wide  and  of  the  teeming  animal  life 
that  accompanied  the  prairie  plants.  It  well  repays  the  effort 
to  trace  the  evolution  of  the  prairie  and  to  become  acquainted 
with  the  typical  plants  and  animals  of  this  prairie  association 

in  as  favorable  localities  as 
are  at  present  available. 

Shoreward  from  the  rush 
zone  in  those  lakes  or  por- 
tions of  lakes  that  are  devel- 
oping into  prairie  there  comes 
a  broad  zone  occupied  by 
sedges  and  grasses.  The  cat- 
tail zone  is  omitted.  This 
sedge  zone  is  more  or  less 
completely  inundated  in  the 
high- water  stages  of  early 
spring,  but  in  the  summer 
may  be  reasonably  dry.  Here 
such  sedges  as  Car  ex  aquati- 
lis,C.  conjuncta  (Fig.  349), 
C.  cristata  (Fig.  350),  C.  liipii- 
liformis  (Fig.  351),  C.  riparia, 
and  C.  stricta  (Fig.  352), 
together  with  some  of  the 
rushes  of  the  preceding  zone, 


Fig.    360. —  Smartweed,    Polygonum 
lapathifolinm. 


are  found.  The  Car  exes  are  grass-Hke  plants  usually  with 
triangular  stems.  There  are  very  many  species,  a  few  of 
which  may  be  recognized  by  the  figures.  Gray's  Botany  will 
be  needed  to  determine  the  many  others.  Such  grasses  as 
the  following  are  distinctive.  They  are  named  in  the  order 
of  their  appearance  from  the  outer  edge  of  the  zone  shore- 
ward: slough  grass  (Fig.  353),  blue-joint  grass  (Fig.  354), 
fowl  meadow  grass   (Fig.  355),  switch  grass   (Fig.  356),   thin 


LAKE  TO  FOREST  OR  PRAIRIE 


247 


grass  (Fig.  357),  Poa  triflora,  etc.  Sampson  thinks  the  first  five 
are  the  typical  and  most  characteristic  ones  in  the  succession 
that  leads  to  the  occupation  of  the  prairie  by  the  Andropogon 
furcatus  (Fig.  358), 
which  marks  the  climax. 
In  summer  these  swamp 
grasses  may  be  luxuri- 
ant enough  to  pay  for 
cutting  to  secure  the 
coarse  marsh  hay  (Fig. 

359)- 

Among  the  grasses 
and  sedges  occur  many 
other  plants,  not  in 
masses  so  as  to  give 
character  to  a  whole 
zone  as  do  the  grasses 
and  sedges,  but  still 
frequently.  The  fern, 
Aspidium  cristatum,  is  a 
common    one    in   such 

marsn  lands.    iLquisetUM  Fig.  361. — Chickweed,  Cerastiuvi  vulgatwn 


Figs.  362-364:  Fig.  362. — Three  species  of  Cardaminc:  C.  Douglassil  at  left; 
leaf  of  C.  bulbosa,  above  at  right;  C.  pcmisylvanica,  right  below;  Fig.  363.— Mer- 
maid weed,  Proserpinaca  palustris;  Fig.  364. — Skull  cap,  Scutellaria  galcriculata. 


248       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Fig.  365.- 
nalis. 


-Cardinal  flower,  Lobelia  cardi- 


fluviatile  is  prevalent. 
Other  forms  are  smart- 
weeds,  Polygonum  lapath- 
ifolium  (Fig.  360)  and 
P.  persicaria,  chickweed 
(Fig.  361),  bitter  cress  (Fig. 
362),  Viola  Man  da,  vaQVYRdiXd 
weed  (Fig.  363),  skull  cap 
(Fig.  364),  cardinal  flower 
(Fig.  365). 

The  grass  and  sedge 
formation  described  above 
may  give  place  to  the 
prairie,  at  first  to  the  wet 
prairie  and  finally  to  the 
typical  upland  prairie.  Both 
of  these  areas  manifest 
marked  seasonal  changes  as 
indeed  do  most  areas.  One 
set  of  plants  comes  on  to 
maturity,  blossoms,  fruits, 
and  gives  way  to  a  later  set, 
which  in  turn  becomes  in- 
conspicuous as  some  other 
assumes  for  the  time  being 
the  conspicuous  role.  Thus 
Viola  hlanda  and  V.  peda- 
tifida  blossom  early  on 
the  prairie,  shooting  star 

(Fig.  366)  comes  then,  wild 
hyacinth  (Fig.  367)  by  June, 
then  wild  onions  (Fig.  368), 
Culver's  root  (Fig.  369)  and 
golden  old  man  (Fig.  370) 
follow.    Brown-eyed  Susans 


LAKE  TO  FOREST  OR  PRAIRIE 


249 


(Fig.  371)  are  pre-empting  attention  by  July,  as  are  also  the  cone- 
flowers  (Fig.  372);  the  purple  ones  are  notably  brilliant.  Then 
in  late  summer  come  blazing 
stars  (Fig.  133),  rosin  weed 
(Fig.  373),  asters,  goldenrods, 
and  beggar-ticks,  whose  fruits 
you  carry  away  as  souvenirs 
nolens  volens.  The  above- 
mentioned  plants,  because 
they  are  conspicuous  when  in 
blossom,  give  a  constantly 
changing  character  to  the 
prairie,  yet,  after  all,  the 
dominant  things  are  the 
prairie  grasses  such  as  blue- 


FiG.  367. — Wild  hyacinth,    Camassia 
esculenta. 


Fig.  366. — Shooting  star,   Dodeca- 
theon  meadia. 

stem,  Andropogon  furcatiis, 
and  dropseed,  Sporobolus 
cryptandrus  (Fig.  374),  that 
by  their  very  abundance  and 
uniformity  fail  to  strike 
attention. 

As  the  prairie  with  domi- 
nating clay  soil  becomes 
pretty  dry  such  plants  as  the 
rose  pink  prairie  phlox  (Fig. 
375),  prickly  lettuce  (Fig.  62), 
butterfly  weed,  prairie  thistle, 
everlasting,  rattlesnake  master 
(Fig.   376)    become    more 


250       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


conspicuous,    replacing    in    part    the   above-mentioned    forms. 
On  thin-soiled  prairie,  or  prairie  with  sandy  soil,  the  pink  and 


Fig.  368. — Wild  onion  in  blossom,  Allium  cernuum 

white  prairie  clover,  Petalostemum  (Fig.  377),  and  lead  plant 
(Fig.  378)  are  apt  to  predominate,  while  such  typical  plants  of 
the  clay-soil  prairie 
as  Silphium  terehin- 
thinaceum,  S.lacinia- 
tum,  and  Eryngium  jjf 
yuccifolium  are  Al..^ 
rare.  W^m 

Naturally  in  any    ^^^^, 
region  with  as  dis- 
tinctive a  group  of 
plants   as  exists  in 
the  prairie  there  will 

.      .  Fig.  369  Fig.  370 

be    a    characteristic  p^^g  ^^^^  ^^^.  p^^   369 —culver's  root,  Veronica 

SSSemblage      of    virginica;  Fig.  370. — Golden  old  man,  Zizia  aurea. 


LAKE  TO  FOREST  OR  PRAIRIE 


251 


animals.     Indeed,  the  transition,   as  one  goes   from   the  oak- 
hickory  or   the  maple-beech  forest   to   the  adjoining   prairie, 


Fig.  371. 


Fig.  372. — Coneflower, 
Brauneria  purpurea. 


-Brown-eyed  Susans,  Rudheckia  hirta 

is  so  abrupt,  the  new  animals  and  plants 
so  strikingly  dissimilar  to  those  of  the 
forest,  that  even  the  casual  observer  must 
be  struck  by  the  change.  The  contrast  is 
even  enhanced  by  going  through  the 
border  of  wild  shrubs,  hawthorn,  trembling 
asps,  and  sumacs,  so  characteristic  at  the 
edge  of  the  oak-hickory  association  with 
the  distinctive  animal  and  plant  life  that 
belongs  to  such  a  border. 

One  of  the  most  characteristic  features 
of  the  wet  prairie  or  even  of  the  upland 


252       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


t*     \ 


X 


r    fA// 


^^M'"'^- 

*<^:^-' 


prairie,  if  its  subsoil  is  clay,  is 
the  abundance  of  chimneys  of 
the  burrowing  crayfish,  Cam- 
hams  gracilis  (green)  (Fig.  379) 
and  C.  diogenes  (red).  These 
animals  dig  wells  to  insure 
moist  retreats  in  the  dry  sum- 
mertime and  safe  ones  at  all 
times.  The  excavated  mate- 
rial is  often  piled  as  a  chim- 
ney about  the  hole.  The 
crayfish  lives  near  the  top  of 
the  burrow  but  drops  back 
when  frightened.  He  wanders 
out  from  his  castle  turret  to 
seek  food,  hunting  largely  at 
dusk.  Earthworms  are  com- 
mon in  the  rich  prairie  soils, 
particularly  the  big  night 
crawler.  Larvae  of  the  June 
beetle   are   abundant  in  the 


Fig.  373.     Robims  cL-d,  Sit  phi  urn 
terebinthinacemn. 

subterranean  layer  of  the 
upland  prairie.  The  ant, 
Formoso  sub politavar  neo- 
gagates,  builds  large  hills, 
burrowing  into  the  ground 
beneath  them.  The  star- 
nosed  mole,  similar  to  the 
common  mole,  but  easily 
recognized  by  its  large 
front  feet  with  heavy  claws 
and  the  fringed  disk  on  its 
nose,  burrows  beneath  the  fig.  374  fig.  375 

sod  for  worms  and  larvae.    ^   ^''^^■274, 375:  Fig.  374^-Dropseed  grass, 

Ciporobokis    cryptandrus;     Fig.    375. —  Praine 

The  famihar  striped  gopher  phlox,  Phlox  pilosa. 


LAKE  TO  FOREST  OR  PRAIRIE 


253 


(Fig.  380),  ground  squirrel,  or  thirteen-lined  spermophile,  and 
Franklin's  spermophile  or  gray  gopher  (Fig.  319),  dig  their 
retreats  here  and  scurry  to  them  from  their  foraging  trips. 
The  pocket  gopher   (Fig.   381)  is  also  a  resident  of  the  high 


Fig.  376. — Rattlesnake  master,  Eryngium  yuccifolium 

prairie.     The  bulging  cheek  pockets  stored  with  food  character- 
ize this  little  rodent. 

The  field  mouse,  Microtus  ochrogaster,  builds  its  nest  of  grass, 
sometimes  hiding  it  under  a  log  in  the  adjacent  forest.  It  lives 
by  hunting  for  provender  among  the  grasses.  It  is  similar  to 
the  Pennsylvania  meadow  mouse  (Fig.  382)  but  has  a  gray- 
brown  back,  while  the  Pennsylvania  meadow  mouse  has  a 
dark  brown  back.     The  prairie  deer  mouse,  5.25  inches  long, 


254       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

gray-brown   above,    white   below,    with   gray   feet   and   white 
toes,  is  fairly  common.     It  is  quite  like  the  white-footed  deer 

mouse  (Fig.  287)  but 
this  has  pure  white 
feet.  The  Pennsyl- 
vania meadow  mouse 
is  more  prevalent  in 
the  wet  prairie. 
Certain  birds  nest  on 
the  ground  of  the 
open  prairie;  the 
most  characteristic 
are  the  bobolink,  the 
meadow  lark,  its  nest 

Fig.  377  Fig. 378 

Figs.  377,  378:   Fig.  377.— Prairie  clover,  Peta-    ^^  ^he  end  of  a  grassy 
lostcmmn  purpnrciim;    Fig.  378.— Lead  plant,  ylwor-    tunnel,  the  dickcissel, 

pha  cancscens.  ^-j^g  vesper  spar  row, 

the  grasshopper   sparrow,    the   prairie   horned   lark,    the   lark 
bunting,  and  the  prairie  chicken.     The  first  three  mentioned 


Fig.  379. — Chimney  of  burrowing  crayfish,  Cambarus  diogcnes 


LAKE  TO  FOREST  OR  PRAIRIE 


255 


are  found  most  often  in  the  wet  prairie;  the  others  belong  to 
the  dry  prairie  association.  Prairie  horned  lark  and  lark  bunt- 
ing are  not  very  common  residents  of  the  Chicago  region. 

The  common  toad  is  preva- 
lent, as  would  be  expected,  in 
a  region  where  insects  are  so 
common.  The  green  snake, 
Leiopellis  vernalis,  green  above, 
greenish  white  below,  is  the 
characteristic  snake,  especially 
in  the  moist  prairie,  while  the 
prairie  garter  snake  is  more 
common  on  the  dry  prairie, 
though  becoming  rare. 

The  short  wing  and  the 
long- winged  grouse  locusts,  Tettigidea  parvipennls,  T.  pennata, 
live  on  the  ground  of  the  wet  prairie.  They  are  small,  obscure 
because  of  their  ground  color,  and  appear  in  the  spring.     Later 


Fig.   380. — Striped    gopher,    Citellus 
tridecemlineatus. 


Fig.  381. — Pocket  gopher,  Geomys  hursarius 

these  small  forms  give  place  to  the  more  familiar  locusts  and 
grasshoppers  of  the  summertime.  The  characteristic  ones  of 
the  wet  prairie  are  Xiphidmm  fasciatum,  the  red-legged  locust 
(Fig.  383),  the  two-lined  locust  (Fig.  383),  and  the  short- winged 


256       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


locust  (Fig.  383).  Those  of  the  dry  prairie  are  the  field  grass- 
hopper, the  glade  grasshopper,  the  straight-lance  and  the 
meadow  grasshopper  (Fig.  s^s)- 


Fig.  382. 
prints. 


-Pennsylvania  meadow  mouse,  Microtus  pennsylvanicus,  and  foot- 


FiG.  383. — Different  species  of  grasshoppers:  a,  the  two-lined  locust,  Melano- 
plus  bivittatus;  b,  the  red-legged  locust,  M.  femur-riibrum;  c,  the  short-winged 
meadow  grasshopper,  XipJiidimn  brevipenne;  d,  the  common  meadow  grasshopper, 
Orchelmimn  vulgare;  e,  the  sprinkled  grasshopper,  Chlocaltis  conspersa;  f,  the 
green-legged  locust,  Melanoplus  viridipes. 

Many  larvae  are  found  feeding  on  the  grasses  and  associated 
plants,  particularly  on  the  low  prairie  where  such  plants  remain 


387 


***%.,, 


"    t.^ 


386 


:<B"i^.'  I 


r/"» 


C.V  f. 


Figs,  384-387:  Fig.  384. — Grass  sawfly  (a),  larvae  on  grass;  (b),  larva 
enlarged;  (c),  adult  female.  After  Marlatt;  Fig.  385. — Dingy  cutworm  (h)  and 
moth  (a),  Feltia  suhgothica.  After  Felt;  Fig.  386.- — Salt-marsh  caterpillar  and  moth, 
Estigmena  acraea.  After  Forbes;  Fig.  387. — The  "yellow  bear"  (a)  and  moth  (6), 
Diacrisia  virginica.    After  Forbes. 


258       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

succulent  for  a  long  time.  Sawfly  larvae  (Fig.  384)  appear  late 
in  the  spring.  Moth  and  butterfly  larvae  are  common,  as  are 
also  the  adults.  The  cutworm  moth  (Fig.  385)  flies  out  of  the 
short  grass  in  the  early  spring  and  remains  abundant  all 
summer.  Its  larvae  feed  on  the  wild  strawberry  plant.  The 
salt-marsh  caterpillar  (Fig.  386)  and  the  ^' ghost  moth"  that 


.-.■/S*?"^ 


r         ^ 


M^-W^^C^^^ 


Fig.  388. — The  Isabella  tiger  moth,  Isia  Isabella,  and  its  larva,  the  "woolly 
bear"  caterpillar,  from  Cornell  Nature  Leaflet. 

comes  from  it,  the  ''yellow  bear"  (Fig.  387),  and  the  hedge- 
hog caterpillars  and  their  moths,  including  the  Isabella  moth 
the  caterpillar  of  which  is  known  as  the  ''woolly  bear" 
(Fig.  s^^))  ^^^  common  in  aU  seasons,  the  caterpillars  espe- 
cially so  in  the  fall. 

Then  every  plant  of  the  prairie  has  its  associated  animals, 
so  a  succession  of  animal  forms  appears  as  the  spring  plants 
give  place  to  the  summer  ones  and  these  in  turn  to  the  autumn 
types. 


CHAPTER   XII 
LAKE  BLUFF,  RAVINE,  AND  RIVER  VALLEY 

RAIRIE  and  climax  forest,  once  estab- 
lished, are  not  assured  of  permanency. 
Indeed,  the  forces  that  operate  to  des- 
troy them  are  often  at  work  contem- 
poraneously with  those  that  complete 
their  formation. 

Along  the  lake  shore  wave  action  is 
in  many  places  undercutting  the  bluffs 
so  that  adjacent  forest  or  prairie  is  sliced  off  gradually  to 
disappear  in  the  insatiable  maw  of  the  lake.  The  plant 
and  animal  life  of  this  unstable  bluff  side  is  quite  different 
from  that  of  the  prairie  or  forest  it  replaces.  Again,  a  runnel 
starts  in  the  spring  freshets,  courses  through  the  prairie  or 
the  forest,  excavating  a  shght  depression.  Year  after  year  this 
deepens  and  widens  so  that  the  prairie  or  woodland  is  invaded 
by  a  growing  ravine  that  produces  extensive  changes  in  the  flora 
and  fauna.  In  time  the  ravine  widens  to  a  miniature  river 
valley.  It  is  interesting  to  trace  these  changes  produced  as 
bluff  and  ravine  and  river  valley  develop. 

The  annual  winter  storms  cut  away  the  underpinning  of  such 
bluffs,  the  upper  portions  slide  down,  carrying  trees  and  shrubs 
from  the  higher  level  to  destruction  in  the  wave-washed  base 
(Fig.  i).  Naturally,  few  plants  and  animals  can  maintain  exist- 
ence in  such  an  unstable  environment.  The  surface  of  such  a 
bluff  is  often  largely  free  from  vegetation  or  scantily  covered  at 
best  with  such  forms  as  can  maintain  a  temporary  footing  on  the 
insecure  soil. 

Moreover,  such  nearly  naked  bluffs  have  a  high  rate  of 
evaporation.     The  upper  portions  especially  are  dry  because  the 


259 


26o       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

soil  water  drains  out  so  readily.  They  are  exposed,  too,  to  the 
cold  winds  from  the  lake.  It  is  to  be  expected,  therefore,  that 
the  plants,  especially  of  the  crest,  will  be  xerophytic  and  hardy 
(Fig.  389).  White  pines,  jack  pines,  cotton  wood,  large-  and 
small-toothed  aspens,  red  cedar,  white  birch,  spreading  juniper, 
leatherleaf,  red-osier  dogwood,  glaucous  willow,  and  staghorn 
sumac  are  the  characteristic  shrubs  and  trees  on  those  bluffs 
that  are  somewhat  stabihzed.  Sweet  clover  and  many  other 
common  weeds  that  can  stand  severe  exposure  are  found,  such 


^^ 

« 

f  J* 

i-''ty 

■^'''' 

I 

wmj- .  -i^^^j^^^M 

■jb  ^ ' 

li 

V             jok  -J 

li 

4 

M 

K^ 


k^^  _.#  -^^^  . 

^'•15^:#^*\     ■          .           .■            %'*^'        *'^''P^'v-^i^*ttv-.                                                                                        .        ■             .          ■       ■     V 

mn 

j^^^^^^j^^^^^^^l^^jgll^v^^^^^               -  'MMMim    f   )^^!^|Mi 

Fig.  389.— Lake  shore  bluff  with  xerophytic  vegetation 

as  mullein,  Canada  thistle,  dock,  Russian  thistle,  the  horsetails, 
Equisetum  hyemale  (Fig.  390),  and  E.  arvensis. 

The  animal  life  is  scant  but  is  as  distinctive  as  the  plant.  As 
in  the  Dunes  we  found  a  tiger  beetle,  characteristic  of  nearly 
every  zone,  so  here  we  find  Cicindela  purpurea  limhalis  (Fig.  145) 
confined  to  this  particular  habitat,  chiefly  on  the  wet  clay  bluffs. 
The  holes  of  the  larvae  are  common  on  bare  spots,  and  the 
adults  are  abundant  in  midsummer,  hunting  over  the  sparse 
vegetation  for  insect  prey,  particularly  the  sweet  clover.  The 
clay-bank  spider,  a  large  black  one,  Pardosa  lapidicina  (Fig.  391), 


LAKE  BLUFF,  RAVINE,  AND  RIVER  VALLEY 


261 


Fig.  390. — Common 
scouring  rush,  Equi- 
setum  hyemale. 


shares  this  hunting  ground.  Some  clay-bank  wasps  hunt  here, 
and  the  Carolina  locust  is  common.  Wherever  the  cliff  is  stable 
enough  to  develop  shrubs  and  tree  thickets  the  plants 
and  animals  of  the  mesophytic  forest  margins  appear 
(see  p.  230). 

The  ravine  in  clay  soil  attains  at  its  mouth  much 
the  same  appearance  as  does  the  lake  shore  clay  bluff 
(Fig.  392),  and  the  animals  and  plants  found  are  similar. 
It  is  evident,  however,  that  the  ravine  will  vary  in 
character  according  to  the  sort  of  material  in  which  it 
is  forming.  In  loose  and  friable  soil  it  will  develop 
rapidly,  its  sides  will  wear  by  erosive  action 
with  celerity,  and  it  will  in  a  relatively  short 
time  be  broad  in  comparison  with  its  depth, 
so  its  sides  will  have  gradual  slopes.  In 
clay  soil,  however,  the  stream  cuts  into  the 
more  resistant  material  more  rapidly  than 
the  less  vigorous  agents  of  erosion,  atmospheric  disintegration, 
rain,  and  wind  affect  the  sides.  The  ravine,  therefore,  will  be 
deep  in  comparison  with  its  width 
and  will  have  steep  slopes  (Fig.  6). 
In  rock  only  the  stream  is  powerful 
enough  to  erode  rapidly.  The  sides 
wear  away  very  slowly,  so  the  rock 
ravine  has  very  steep,  often  verti- 
cal, sides.  Ravines  of  the  first  t5^e, 
hardly  ravines  at  all,  but  miniature 
valleys,  are  wide  open  to  the  sun, 
so  that  light,  heat,  and  the  rate  of 
evaporation  is  much  as  it  is  else- 
where in  the  vicinity.  The  slopes 
are  dry,  however,  since  water  runs 
off  them  well  and  seeps  out  into  the 
lower  stream  bed.  But  in  ravines  in  clay  soil  the  sun  has 
access  only  at  certain  times  of  the  day;  they  are,  therefore,  cool 


Fig.  391. — Clay-bank  spider,  Par- 
do  sa  lapidicina.    After  Shelf ord. 


262       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

and  moist.  Evaporation  goes  on  very  slowly.  These  same 
conditions  prevail  even  in  a  more  emphatic  manner  in  the 
rock  ravine.  In  the  latter  type  especially,  springs  emanating 
through  rock  cracks  and  crevices  often  keep  the  sides  drip- 
ping wet. 

The  ravine  is  naturally  most  completely  developed  at  or 
near  its  mouth,  for  it  was  at  this  end  that  it  began  cutting  back 
into  the  highland.     At  its  head  it  is  still  a  young  ravine,  pushing 


-%^ 


>i 


-«*« 


i 


Fig.  392. — Mouth  of  ravine  at  the  lake  shore 

back  gradually  into  the  prairie  or  forest.  As  one  follows  down 
the  ravine  older  and  older  stages  are  encountered.  At  first  it 
is  a  mere  gully  with  a  tiny  trickle  in  it,  except  during  spring 
freshets.  Then  it  deepens  and  widens  into  a  young  V-shaped 
ravine  with  a  growing  stream  as  tributary  guUies  add  their 
contributions.  In  clay  and  rock  the  sides  are  very  steep — so 
steep  that  the  rock  or  clay  slides  down  in  landslides  into  the 
bottom,  often  producing  bare  areas  so  unstable  that  plants  can- 
not get  a  foothold.  Still  farther  down  the  growing  brook  begins 
to  cut  into  one  side,  then  the  other,  as  it  assumes  a  tortuous 
course  due  to  varying  obstructions.     So  the  stream  meanders 


LAKE  BLUFF,  RAVINE,  AND  RIVER  VALLEY 


263 


back  and  forth,  depositing  in  some  spots  what  it  wears  away  in 
others.  The  bottom  of  the  ravine  widens  into  a  miniature  flood 
plain.  The  sides  become  less  steep.  Possibly  in  the  lower 
reaches  the  stream  has  cut  down  nearly  to  the  level  of  the  lake  or 
larger  stream  into  which  it  flows  and  so  runs  sluggishly.  It  is 
no  longer  a  brawling  brook,  but  a  placid  little  creek.  The 
ravine  has  broadened  into  a  miniature  valley.     All  these  stages 


Fig.  393. — Rock  ravine  with  vegetation  on  the  sides,  near  the  "Sag" 


are  admirably  seen  along  the  north  shore  of  the  lake  where  the 
clay  bluffs  abut  upon  the  shore  (Figs.  5  and  6). 

Since  it  is  only  the  stream  that  is  capable  of  rapid  erosion  in 
rock,  the  rock  ravine  is  prone  to  end  at  its  upper  end  in  a  water 
fall  (Fig.  9).  This  fall  gradually  retreats  as  the  stream  eats  its 
way  through  the  rock.  In  relatively  soft  rock  the  fall  is  likely 
to  be  quite  a  high  one,  and  the  ravine  ends  abruptly.  If  the 
rock  is  hard,  a  series  of  rapids  may  replace  the  fall,  and  the 
ravine  gradually  becomes  more  and  more  shallow  to  its  head. 


264       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


It  is  evident  that  the  edges  of  the  ravine  slope  must  be  dry 
areas,  for  the  soil  moisture  will  readily  drain  out  into  the  ravine. 
The  deeper  the  ravine,  the  farther  back  from  its  edge  the  dry 

area  will  run.  As  you  approach  the  rock 
ravine  through  the  forest  in  the  Starved 
Rock  region  there  is  a  marked  change 
in  the  vegetation,  the  mesophytic  forms 
giving  way  to  xerophytic  sorts.  Black 
oaks  replace  the  red  and  white.  Such 
shrubs  as  panicled  dogwood,  sumac, 
chokecherry,  and  ninebark,  are  charac- 
teristic. Patches  of  hairycap  moss  and 
horsetails,  indicative  of  xerophytic  con- 
ditions, appear  along  the  edges  of  the 
Fig.  394.— Sarsaparilla,  ravine  openings.  Junipers  are  growing 
Aralia  nudicaulis.  ^^^  ^^^^  deciduous  shrubs  as  the  blue- 

berry and  huckleberry.  These  and  such  flowering  plants  as  the 
false  lily-of-the-valley  and  bastard  toadflax  found  growing  here 
are  characteristic  of  the  pine  region  in 
the  Dunes. 

The  sides  of  the  ravines  support  an 
abundant  vegetation  if  they  are  sloping 
and  have  some  soil.  Cinnamon  and 
interrupted  ferns  may  grow  on  the  banks. 
Where  the  sides  are  steeper  still  and 
rocky,  red  cedar,  balsam,  ninebark, 
gooseberry,  and  other  plants  gain  pre- 
carious footings  (Fig.  393) ;  columbine, 
bluebells,  Prenanthes,  sarsaparilla  (Fig. 
394),  shooting  star  occasionally,  and  such  Fig.  395.— Fragile  fern, 
ferns  as  the  fragile  fern  (Fig.  395)  and  y^opensjragi  is. 
bladder  ferns  (Fig.  396)  are  to  be  found  growing  in  the  cracks 
and  crevices.  In  all  of  the  ravines  it  is  noticeable  that  vegeta- 
tion is  much  more  abundant  on  the  shady  side  than  on  the  side 
exposed  to  the  sun.     Farther  down  in  the  bottom  of  the  ravine 


LAKE  BLUFF,  RAVINE,  AND  RIVER  VALLEY 


265 


the  walls  are  found  plastered  with  liverworts,  Conocephalus 
being  the  prevalent  one — Marchantia  (Fig.  397)  less  common. 
Mosses  are  abundant.  The  purple- 
stemmed  cliff  brake  (Pellaea  atro purpurea), 
recognized  readily  by  the  location  and 
its  slender  purple  stem,  is  noticeable. 
Selaginella  grows  in  beautiful  masses 
(Fig.  398) ;  wild  hydrangea  is  present  as 
an  interesting  shrub  in  the  ravine  bottom 
(Fig.  399) ;  touch-me-not,  early  saxifrage, 
river  horsetail,  and  other  plants  demand- 
ing much  shade  and  moisture,  are  preva- 
lent in  the  bottoms  of  the  ravines.     Bank    c^lTpf^sMi'^^^^^ 

swallows   and    occasionally    rough-winged     right,  under  side  of  frond; 
swallows    nest    on    shelves    of    the    rocks.     ^PPer  center,  one  sorus. 

The  mourning  dove,  the  wood  peewee  and  ruby-throated  hum- 
mingbird build  on  the  overhanging  shrubs.     Snails  crawl  about 


Figs.  397-398:  Fig.  397. — A  liverwort,  Marchantia  polymorpha,  bearing 
archegonial  branches.  Upper  right,  portion  of  thallus  with  gemmae  cups.  After 
Atkinson;  Fig.  398. — Selaginella.     After  Andrews, 


266       A  NATURALIST.  IN  THE  GREAT  LAKES  REGION 


,■  r^ 


m 


^'"vlJTfc 


400, 


402 


4  01 


405  ■ 


406 


407 


Figs.  399-407:  Fig.  399. — Meadow  rue,  Thalictrum  dasycarpum;  Fig.  400. — 
Boneset,  Eiipatorimn  pcrfoliatmn;  Fig.  401. — Queen  Anne's  lace,  Daucus  carota; 
Fig.  402. — Wild  parsnip,  Pastinaca  saliva;  Fig.  403. — Angelica,  Angelica  atro- 
purpurca;  Fig.  404. — Alumroot,  Heuchcra  americana;  Fig.  405. — ^^llitlo^v  grass, 
Draba  caroliniana;  Fig.  406. — Rattlebox,  Crolalaria  sagittalis;  Fig.  407. — Walking 
fern,  Camptosorus  rhizophyllus. 


LAKE  BLUFF,  RAVINE,  AND  RIVER  VALLEY 


267 


the  moist  sides  of  the  ravines.     Polygyra  clausa  and  P.  thyroides 
are  the  most  common  in  the  ravines. 

The  clay  ravine  presents  a  slope  on  which  the  most  char- 
acteristic trees  are  the  water  beech  and  hop  hornbeam,  while 


Fig.   408. — Wild   hydrangea,   Hydrangea   arborescens,   in    French    Canyon, 
Starved  Rock. 

witch-hazel  is  likely  to  be  the  dominant  shrub.  Hepatica, 
bloodroot,  meadow  rue  (Fig.  399),  wood  betony,  Prenanthes, 
and  maidenhair  ferns  are  likely  to  be  common  on  the  lower  por- 
tions of  the  slopes.  More  xerophytic  forms,  such  as  wild  sar- 
saparilla  and  false  Solomon's  seal,  are  found  on  the  upper  slopes, 
while  on  the  bottom,  especially  if  a  flood  plain  is  developing, 


268       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

basswood,  the  elms,  ash,  soft  maple,  elderberry,  maple-leaf  vibur- 
num, boneset   (Fig.  400),  Queen  Anne's  lace  (Fig.  401),  wild 


Fig.  409. — Rock  polypody,  Poly  podium  vulgarc,  on  cliff  at  Starved  Rock 

parsnip  (Fig.  402),  and  Angelica   (Fig.  403)   are  likely   to  be 
present. 

Among  the  birds  Phoebe,  wood  peewee,  chewink,  bob  white, 
and  whippoorwill  are  perhaps  the  commonest  forms.  The  lance- 
head  dragon  fly,  whose  nymph  is  found  in  the  pools  of  the  stream^ 


LAKE  BLUFF,  RAVINE,  AND  RIVER  VALLEY  269 

is  very  conspicuous.  It  is  a  large  dragon  fly  with  lance-shaped 
yellow  spots  along  the  back  of  the  abdomen,  and  two  con- 
spicuous yellow  bars  on  each  side  of  the  thorax.  Snails  are 
fairly  abundant  also  in  the  lower  portion  of 
the  clay  ravine;  the  white-lipped  snail, 
Polygyra  thyroides,  Pyramidula  alternata, 
Pyramidida  solitaria,  and  Circinaria  concava 
are  the  most  common  ones.  The  green  tiger 
beetle  so  characteristic  of  the  climax  forest 
is  also  abundant  here. 

The  broad,  open  ravine,  which  develops  as 
erosion   proceeds  and  the  sides  of   the   steep       ^ic    410— Toad 
clay  ravine  wear  away,  is  so  like  the  margin    bug,  Gelastocoris 
of  the  customary  river  valley  that  no  special    ^^"  ^^"^• 
mention  need  be  made  of  it;    the  description  below  will  fit  it 
fairly  well. 

The  valley  of  the  river  that  is  cutting  through  rock  as  is  the 
Illinois  at  Starved  Rock,  the  Rock  River  at  Oregon  and  Grand 

Detour,  the  Wisconsin  in  the  neighborhood 
of  the  Dalles,  is  bordered  by  steep  rock  bluft's. 
The  vegetation  and  animal  life  on  these  differ 
quite  decidedly  from  that  of  the  steep  sides 
of  the  ravines,   for  the  river  valley  is  wide 
open   to   the  sun's  rays.     Such   rocky  river 
bluffs  are  dry  and  hot.     The  top  of  the  bluff 
(Fig.    7)    has    a   tree  and  shrub  population 
much  Hke   that  of  the  crest  of  the  ravine, 
Fig. '411^— Hooded    namely,  white  pine,  red  cedar,  white  cedar, 
grouse  locust,  Pam-    June  berry,  spreading  juniper,  blueberry, 
tcttixcucullatus.  After    huckleberry,   ninebark,    red   elderberry,   etc. 
"^^^^"  In  the  rock  crevices  near  the  top  of  the  bkiff 

the  rock  polypody  fern  is  common  (Fig.  409).  The  sides  of  such 
bluffs  support  columbine,  bluebell,  alumroot  (Fig.  404),  whitlow 
grass  (Fig.  405),  rattlebox  (Fig.  406),  sarsaparilla,  spiderwort, 
Prenanthes,  and  occasionally  walking  fern  (Fig.  407). 


2  70       A  NATURALIST  LY  THE  GREAT  LAKES  REGION 


Fig.  412. — The  spotted  sandpiper. 
Forbush. 


After 


The  steep  soil  slopes  that  He  at  the  base  of  the  rocky  cliffs 

bear  a  forest  of  black,  red,  and  white  oaks,  with  chokecherry,hop 

tree,  water  beech,  hop  hornbeam — forms  which  are  characteristic 

of  such  slopes.  Witch- 
hazel  is  the  predominant 
shrub.  The  ground  is 
covered  with  large  areas  of 
the  cinnamon  fern  and, 
lower  down,  the  inter- 
rupted fern. 

There  is  an  abundant 
bird  population  in  these 
wooded  slopes.  Wood 
thrush,  hermit  thrush,  Wil- 
son's  thrush,  the  ovenbird, 
indigo  bunting,  cardinal, 
black-billed  cuckoo,  crested 
flycatcher,    and  Baltimore 

oriole  are  among  the  commonest  inhabitants.    Chickadees  nest 

in  the  old  woodpecker  holes. 

On    these   moist   slopes    snails  are  particularly    abundant. 

Practically  all  the  Polygyras  of  the  Chicago  area  are  found  here. 

P.    alholahris   and    clausa,  fra- 

terna,  fraudulent  a,    hirsuta, 

inflecta,   monodon,   midtilineata, 

oppressa,  pall  lata,  pennsylvanica, 

tliyroides,  Pyramidida  alternata, 

solitaria,  perspectiva;  Omphalina 

fuliginosa,  friahilis;    Circinaria 

concava;    Zonitoides    arhoreus — 

these  are  all  present.     In  the  early  morning  after  a  shower  or 

after  a  heavy  dew  the  ground  and  the  low  vegetation  is  fairly 

ahve  with  these  numerous  species.     They  are  common  in  the 

river  bottom  also,  and  are  found  crawling  on  the  paths  and 

roadways  (Figs.  284,  285). 


Fig.    413. — Long-bodied    spider, 
Tctragnatha  labor iosa. 


LAKE  BLUFF,  RAVINE,  AND  RIVER  VALLEY  271 


The  river  bottom  or  the 
flood  plain  association  is  a  very 
constant  one.  It  is  bordered 
by  a  succession  of  zones  on  its 
river  side.  First  there  is  a 
zone  of  bare  sand  or  gravel 
which  is  so  often  inundated 
that  no  plants — unless  it  be 
an  occasional  hardy  annual 
weed — grow  upon  it.  Here 
the  toad  bug  (Fig.  410)  is  often 
found,  the  hooded  grouse 
locust  (Fig.  411),  some  of  the 
same  predatory  ground  beetles 
found  along  the  lake  shore, 
and  the  spotted  (Fig.  412)  and 
solitary  sandpipers.  All  these 
feed  on  small  animals  washed 
ashore  by  the  current.  This 
zone, without  plant  life,  may  be 
designated,  on  its  animal  side, 
the  spotted  sandpiper  zone. 

Next  comes  a  zone  of  low 
rich  soil,  inundated  in  the 
spring  but  which  later  dries 
out  enough  so  it  is  populated 
by  such  weeds  as  ragweed  and 
wild  sunflower.  The  granu- 
lated grouse  locust  (Fig.  216) 
is  found  here  early.  Later 
the  meadow  grasshopper, 
Xiphidium  brevipenne,  ap- 
pears. The  long-bodied 
spider,  Tetragnatha  lahoriosa 
(Fig.   413),     finds     this    a 


j;J 


1 


r.'  t  \  \. 

7 

(, 

i"  -  ^ 

|H  *_ 

' 

i 

-^ 

W^^ 

I^BpR%^ 

,  W#  VM. 

4.-        Wi 

^i 

#  ■    v 

• 

Fig.  414. — Kentucky  coffee  tree 


2  72       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

favorable  hunting  ground.  Succinea  avara  and  S.  retusa  are 
found  crawling  over  the  wet  ground  or  on  the  plants.  These 
snails  are  very  widely  distributed  in  wet  and  marshy  situations. 
This  zone  may  be  called  the  giant  ragweed  zone  from  the  plant 
standpoint,  and  the  Succinea  zone  on  its  animal  side. 

Then  comes  a  zone  of  willows,  chiefly  Salix  nigra  and  S.  longi- 
folia.     The  trees  nearest  the  stream  are  usually  small  ones,  the 


Fig.  415. — Flood  plain  of  river  with  vines  draped  on  trees 

larger  ones  standing  farther  back.  With  these  larger  willows 
are  the  young  white  ash,  elms,  and  soft  maples  that  characterize 
the  beginning  of  the  flood  plain  forest  proper.  When  these  willows 
are  in  blossom  in  the  spring  there  are  present  many  flies,  bees, 
and  pollen-loving  beetles  Hke  the  bumble  beetle.  Later  the 
conspicuous  animal  life  is  the  large  number  of  moth  and  butterfly 
larvae  that  feed  on  the  willow.  Mourning  cloak  and  viceroy 
larvae  are  often  found  in  swarms,  while  the  larvae  of  Cecropia 
are  usually  abundant  and  conspicuous  on  account  of  their  large 
size  during  the  fall.     Those  of  the  Sweetheart  and  Bride  are  less 


416 


419 


420 


421 


423 


4,24 


Figs.  416-424:  Fig.  416. — Bladdernut,  Slaphylea  trifolia;  Fig.  417. —  prickly 
ash,  Zanthoxylum  americanum;  Fig.  418. — Moonseed,  Mcnispcrmum  canadcnsc; 
Fig.  419. — Smilax,  Smilax  hispida;  Fig.  420. — Skunk  cabbage,  Symplocarpus 
foetidus;  Fig.  421. — Cheveril,  Chaerophyllum  procumbens;  Fig.  422. — Fringed  loose- 
strife, Steironcma  ciliatum;  Fig.  423. — Honewort,  Cryptolaenia  canadensis;  Fig. 
424. — Cow  parsnip,  Hieradeum  lanatum. 


274       ^  NATURALIST  IN  THE  GREAT  LAKES  REGION 

conspicuous.  This  zone  is  very  evidently  the  willow  zone  on  its 
plant  side  and  may  be  designated  the  cecropia  larva  zone  on  its 
animal  side. 

Farther  back  from  the  stream  is  the  flood-plain  forest  proper. 
Red  and  white  elms,  white  and  black  and  blue  ash,  basswood, 
soft  maple,  hackberry,  black  cherry,  black  walnut,  sycamore,  and 
black  willow  are  the  common  trees,  w^ith  white  elm,  white  ash,  and 
soft  maple  dominant  members  of  the  association.  In  addition, 
the  Kentucky  coffee  tree,  Gyfnnocladus  dioica  (Fig.  414),  is  com- 
mon a  little  farther  south,  and  when  one  gets  away  from  the  lake 
in  the  Chicago  area,  the  tulip  tree,  pawpaw,  flowering  dogwood, 
and  redbud  are  often  found  in  the  river-bottom  association. 


Fig.  425. — Short-tailed  shrew,  Blarina  brevicaudata,  and  footprints 

Of  the  smaller  trees  the  hawthorn,  American  crab,  chokecherry, 
and  the  hop  tree  are  conspicuous.  The  shrubs  that  are  character- 
istic are  buttonbush,  burning  bush,  or  wahoo,  elderberry,  bladder 
nut  (Fig.  416),  nannyberry,  prickly  ash  (Fig.  417),  and  in  some 
places  the  strawberry  bush  covers  large  areas  of  the  ground. 

The  river  bottom  association  is  characterized  by  many  w^oody 
vines,  some  of  which  climb  up  the  low  trees  and  drape  them  with 
dense  festoons  (Fig.  415).  Such  are  the  Virginia  creeper,  poison 
ivy,  bittersweet,  honeysuckle,  moonseed  (Fig.  418),  and  the 
wolf  grape.  Several  species  of  smilax  are  also  common  (Fig.  419). 
'  As  in  the  climax  forest  there  is  present  here  an  abundance  of 
spring  herbs  that  bear  blossoms  and  set  their  fruit  before  the 
dense  shade  of  summer  is  produced  by  the  thick  foHage  of  the 
trees  and  shrubs.     Skunk  cabbage  (Fig.  420)  and  marsh  mari- 


LAKE  BLUFF,  RAVINE,  AND  FIVER  VALLEY  275 

gold  come  early  in  the  wet  areas.  Spring  beauty  often  covers 
the  ground  completely,  and  later  the  phlox  {Phlox  divaricata) 
may  cover  acres  with  its  bloom.  Bloodroot,  bedstraw,  cheveril 
(Fig.  421),  blue  cohosh,  dogtooth  violet,  fringed  loosestrife  (Fig. 
422),  geranium,  wild  ginger,  honewort  (Fig.  423),  leeks  and 
onions,  false  mermaid  weed,  cow  parsnip  (Fig.  424),  Solomon's 
seal,  both  true  and  false,  sweet  cicely,  spring  cress  of  several 
species  (Fig.  362),  trillium,  toothwort  (Fig.  55),  violets,  and 
waterleaf  are  the  common  members. 

It  is  interesting  to  note  the  arrangement  of  these  flood-plain 
zones  on  an  island  in  midstream.  Some  shift  of  current  or  some 
obstruction  causes  the  sediment  held  by  the  river  to  deposit,  and 
so  a  mud  barrier  forms  in  midstream,  a  patch  of  flood  plain  dis- 
connected from  the  shore.  Such  an  island  grows  on  its  down- 
stream side  because  the  current  is  checked  by  the  obstruction 
and  the  deposit  is  in  the  quiet  waters  below  it.  Vegetation, 
therefore,  appears  on  its  upper  end  as  soon  as  this  portion  dries 
out  sufflciently  to  permit  plant  growth.  For  the  same  reason, 
the  flood  plain  forest  develops  here,  and  successive  zones  extend 
toward  the  lower  end.  Islands  in  a  lake  or  pond  have  their 
zones  arranged  more  or  less  in  concentric  rings  in  contrast  to 
the  longitudinal  zones  of  the  river  island. 

There  is  usually  a  marked  contrast  between  the  vegetation  of 
the  river  valley  and  that  of  the  bordering  hills.  We  have 
already  noted  above  the  vegetation  of  the  rock  hills.  Customa- 
rily the  hills  that  border  the  flood  plain  bear  the  usual  white  oak, 
red  oak-hickory  forest,  which  has  been  considered  in  chapter  x. 

In  most  respects  the  animal  life  of  the  flood-plain  forest  is 
very  like  that  of  the  cHmax  beech-maple  forest,  though  the 
forms  are  not  as  numerous,  as  the  annual  inundation  prevents 
the  permanent  residence  of  many  animals.  The  short-tailed 
shrew  (Fig.  425),  white-footed  deer  mouse  (Fig.  287),  and  com- 
mon mole  (Fig.  286)  are  usually  present.  The  same  beetles  are 
present  on  the  ground  and  in  the  rotting  logs.  The  mollusks 
are  similar  though  not  as  numerous. 


CHAPTER  XIII 
BROOK,  CREEK,  AND   RIVER 

HERE  are  a  number  of  factors  influen- 
cing the  character  of  the  animal  and  plant 
life  of  the  stream,  though  most  of  them 
act  as  indirect  determiners  affecting  the 
quantity  and  character  of  the  gases  con- 
tained in  the  water,  its  acidity  or  alka- 
linity, the  temperature  or  rate  of  flow 
of  the  stream,  which  are  the  principal 
immediate  causes  of  variation  in  the  stream  fauna  and  flora. 

If  the  sources  of  the  water  supply  are  such  that  the  stream 
flows  intermittently,  drying  up  to  form  a  succession  of  stagnant 
pools  when  the  rains  cease — usually  in  midsummer — but  running 
as  a  brook  or  creek  during  the  spring  freshets  or  the  fall  rains, 
the  life  it  contains  will  be  quite  different  from  that  of  the  steadily 
flowing  streams.  A  spring-fed  brook,  because  of  its  low  temper- 
ature, will  support  a  population  quite  unlike  that  of  the  stream 
that  emanates  from  pond  or  swamp.  A  stream  whose  waters 
are  distinctly  acid  from  abundant  decomposing  organic  matter 
or  from  factory  waste  will  have  quite  a  difterent  fauna  and  flora 
from  the  usual  alkahne  stream  of  this  area.  The  population 
of  the  lUinois  River  has  suffered  very  marked  change  in  recent 
years  because  of  the  increase  in  decomposing  organic  matter 
brought  to  it  by  the  Chicago  Drainage  Canal.  Thorn  Creek 
has  largely  lost  its  normal  inhabitants  on  account  of  factory 
waste,  and  a  new  set  of  organisms  have  come  in. 

The  stream  from  source  to  mouth  shows  a  succession  of 
species,  those  of  the  small  brook  giving  place  to  others  that  appear 
as  the  stream  widens  and  deepens.  So  we  may  speak  of  the 
headwaters  or  brook  society,  the  midcourse  or  creek  society, 

276 


BROOK,  CREEK,  AND  RIVER  277 

the  lower  stream  or  river  society,  and  finally  the  estuary  society, 
found  in  the  sluggish,  backed-up  waters  near  the  mouths  of 
some  streams.  The  inflowing  streams,  tributaries  to  the  main 
river,  are  likely  to  display  quite  unlike  inhabitants,  those 
entering  well  down  toward  the  mouth  showing  marked  contrasts 
to  those  entering  up  toward  the  source,  for  the  animals  and 
plants  present  in  the  main  stream,  whence  they  migrate  into  the 
tributaries,  are  so  different  in  the  various  parts  of  the  course. 

Even  in  the  same  region  of  the  stream  the  species  present 
will  vary  according  to  varying  depth  and  rapidity  of  the  current. 
Along  shore  the  water  is  shallow  and  so  relatively  wtII  aerated, 
while  in  the  deeper  portions  of  the  stream  the  volume  below  a 
given  area  of  surface  is  much  greater  and  the  concentration  of 
carbon  dioxide  and  other  gases  of  decomposition  is  higher,  other 
things  being  equal.  So  a  zonation  of  plants  and  animals  from 
shore  outward  may  be  expected.  For  the  same  reason  there  is  a 
zonation  from  the  surface  downward  since  the  oxygen  content 
of  the  surface  layers  is  high  •  as  compared  with  the  bottom 
layers.  This  evidently  will  be  most  marked  in  the  quiet 
stretches.  In  the  rapids  where  the  water  is  constantly  stirred 
from  top  to  bottom  there  will  be  no  such  marked  difference. 
So  in  the  sluggish  stretches  of  the  river  the  ox}'gen  content 
will  be  low,  that  of  carbon  dioxide  high,  while  in  the  rapids 
where  the  water  is  well  aerated  by  its  turmoil  the  reverse  will 
be  true.  Active  forms  demanding  much  oxygen  can  live  in  the 
latter  situations  but  not  in  the  former. 

The  character  of  the  bottom  affects  the  animal  and  plant 
population.  As  a  rule  the  stream  has  its  bottom  covered  with 
rocks  or  coarse  gravel  in  its  most  rapid  stretches,  a  sandy  bottom 
where  it  is  less  rapid  but  still  flowing  quite  vigorously,  and  a  mud 
bottom  in  its  quiet  stretches.  In  part,  the  differences  in  plant  and 
animal  life  on  these  different  bottoms  are  due  to  the  varying  rates 
of  the  current,  but  in  part  they  are  directly  connected  with  the 
character  of  the  bottom  itself.  Some  plants  and  animals,  for 
instance,  are  adapted  by  holdfasts  to  attach  themselves  to  a  rock 


278        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

substratum,  others  burrow  only  in  sand,  and  still  others  require 
the  soft  mud  in  which  to  lie  concealed. 

It  is  evident,  then,  that  streams  present  a  great  variety  of 
habitats  and,  therefore,  a  number  of  animal  and  plant  societies, 
which  may  be  tabulated  somewhat  as  follows : 

A.  Communities  of  the  intermittent  stream 

1.  Intermittent  rapids  society  or  the  Simuliiim  (black 
fly)  association 

2.  Intermittent  pool  society  or  the  Camharus  diogenes 
association 

3.  Permanent  pool  society  or  the  horned  dace  association 

B.  Communities  of  permanent  streams 

4.  The  spring-fed  brook  or  planarian  association 
a)  Of  the  usual  alkaline  stream 

5.  The  very  rapid  water  (lotic)  society  or  the  Hydro- 
psyche  association 

This  is  a  rock-bottom  society  and  may  be  subdivided 
into 

a)  Rapids  of  the  brook,  Johnny  darter  association 
"  h)  Rapids  of  the  creek,  fan-tail  darter  association 

c)  Rapids  of  the  river,  banded  darter  association 

6.  The  moderately  rapid,  sand-bottom  society 

a)  Of  the  brook 
h)  Of  the  creek 
c)  Of  the  river 

rboth   divisible 

7.  The  sluggish  water  surface  association  I  as  the  forego- 


8.  The  sluggish  water  bottom  association 

9.  The  estuary  associations 
10.  The  acid  stream  society 


ing  into  a),  b), 
[c) 


It  would  require  a  volume  rather  than  a  chapter  to  discuss  in 
detail  the  stream  societies  and  subsocieties  with  anything  like 


BROOK,  CREEK,  AND  RIVER  279 

thoroughness.  We  must  be  content,  therefore,  to  indicate 
briefly  changes  in  animal  and  plant  population  as  the  stream 
grows  in  size  from  brook  to  creek  and  to  river.  Then  attention 
may  be  called  to  the  societies  of  rapid  water  as  contrasted  with 
those  of  sluggish  water,  and  finally  we  may  take  up  very  briefly 
the  societies  of  intermittent  streams,  of  spring-fed  streams,  and 
of  acid  streams. 

Take  first  the  distribution  of  some  of  the  river  clams  in  the 
lUinois  River  and  its  branches.  The  data  are  taken  largely 
from  Baker's  "Catalogue  of  the  Mollusca  of  Illinois,"  Bulletin 
of  the  Illinois  State  Laboratory  of  Natural  History,  Volume  VII, 
Article  VI,  and  his  ''Mollusca  of  the  Chicago  Area, "  Part  I,  "The 
Pelecypoda,"  Publication  of  the  Chicago  Academy  of  Sciences. 
The  larger  branches  of  the  Illinois  from  its  mouth  toward  its 
source  are  in  order,  (i)  the  Sangamon,  (2)  the  Spoon,  (3)  the 
Mackinaw,  (4)  the  Vermillion,  (5)  the  Fox,  (6)  the  Kankakee, 
(7)  the  Desplaines.  It  is  the  union  of  the  last  two  that  makes 
the  Illinois.  The  more  important  branches  of  the  Desplaines 
are  (8)  the  DuPage,  (9)  Hickory  Creek,  (10)  Salt  Creek.  The 
smaller  creeks  or  runs  are  mere  brooks  and  do  not  support  a 
clam  population.  Of  the  genus  Lampsilis  only  two  get  up  into 
Salt  Creek,  namely,  L.  luteolus  and  L.  ellipsiformis.  Four  more 
are  found  in  Hickory  Creek,  L.  ventricosa,  L.  fallaciosa,  L.  iris, 
and  L.  parva.  All  of  the  foregoing  except  one,  L.  fallaciosa,  are 
reported  from  DuPage  River,  and  in  addition  four  others,  L.  liga- 
mentina,  L.  anadontoides ,  L.  recta,  and  L.  alata.  All  of  the  fore- 
going are  found  in  the  IlHnois  and  its  larger  branches,  and  in 
addition  six  other  species  that  do  not  get  up  into  the  DespLaines. 

Anadonta  marginata  is  found  in  Hickory  Creek  but  not  in 
Salt  Creek.  A.  grandis  and  A.  grandis  fooliana  are  in  the 
DuPage  but  not  farther  north.  A.  imbecilis  is  in  the  Desplaines 
but  not  in  its  branches.  The  Quadrulas  are  almost  entirely 
confined  to  the  larger  streams.  Q.  rublginosa  is  reported  from 
Salt  Creek  and  Q.  coccinea  from  the  DuPage.  There  are  eighteen 
other  species  in  the  Illinois  and  its  larger  branches  named  above. 


28o        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

Consider  next  the  dragon-fly  nymphs.  I  quote  from  Need- 
ham's  ^'Dragon-FKes  of  IlHnois, "  Bulletin  of  the  Illinois  State 
Laboratory  of  Natural  History,  Volume  VI,  Article  I.  This 
indicates  not  only  that  the  distribution  depends  on  the  size  of 
the  stream  but  also  that  forms  vary  according  to  the  rapidity 
of  the  current  and  the  character  of  the  bottom. 

In  the  larger  rivers,  down  to  the  size  of  the  Mackinaw,  in  places  where 
the  water  flows  with  considerable  current  over  a  rocky  bottom,  Diastatomma 
may  be  looked  for;  where  mud  or  sand  bottom  and  quieter  waters  prevail, 
Epicordulia  and  some  species  of  Gomphiis  may  be  found.  Other  species 
of  Gomphus  occur  in  the  bare  muddy  or  sandy  bottoms  of  the  sloughs  and 
bottom-land  lakes.  In  tree  shaded  waters,  where  driftwood  and  branches 
have  gathered,  or  along  muddy  margms,  especially  among  exposed  roots, 
the  lower  Aeschnidae  may  be  looked  for.  In  bottom-land  lakes  where 
vegetation  is  abundant,  one  may  find  Anax,  Agrionidae,  Mesofhcmis,  Celethe- 
niis,  Tramea  and  Pantala  amongst  the  vegetation,  the  latter  two  especially 
on  more  exposed  shores;  and  Tetragoneuria,  Libcllula,  Epicordulia  and 
Leucorhinia  on  the  bottom  underneath.  If  the  situation  is  inclined  to 
be  marshy,  Pachydiplax,  Perithetnis  and  CeUthemis  wiU  be  scattered  over 
the  bottom ;  and  the  shallowest  and  most  temporary  waters  or  wet  lands  are 
the  especial  home  of  Sympetrum. 

In  the  smaller  and  quicker  flowing  streams,  like  the  upper  Mackinaw 
and  Sangamon,  quite  a  different  series  occurs:  Hageniiis  clinging  to  stones 
and  driftwood  and  amongst  dead  leaves;  Boyeria  and  other  dark  Aeschnidae 
on  submerged  branches,  roots  and  sticks;  Cordulcgaster  and  the  long-legged 
Macromia  hidden  at  the  bottom  in  sheltered  eddies;  Somatochlora;  and 
Anally  Progomphus,  Dromogomphus  and  certain  species  of  Gomphus  bur- 
rowing in  the  sandy  bottom.  In  the  prairie  ponds  and  slow  streams  and 
ditches,  Anax,  Agrionidae,  and  Mesothemis  and  other  Libellididae  occur 
amongst  vegetation,  and  Sympetrium  in  shallower  parts,  while  Lihellida 
and  Pla^herms  will  be  found  where  there  is  more  mud  and  less  vegetation, 
as  in  ditches  and  tile  ponds,  resting  at  the  lower  ends  of  well  defined  tracks. 
In  streams  of  rapid  flow  but  not  especially  rocky  or  shaded,  the  Calop- 
terygidae  are  most  likely  to  be  found,  the  imagoes  fluttering  along  the 
banks. 

Of  the  above-mentioned  th^  Agrionidae  and  the  Calopterygidae 
are  families  of  the  damsel  flies  whose  nymphs  bear  three  leaflike 
tracheal  gills  at  the  posterior  end  of  the  abdomen.     The  basal 


BROOK,  CREEK,  AND  RIVER 


281 


segment  of  the  antennae  is  nearly  round  in  the  former,  very 
elongate  in  the  latter.  The  rest  are  included  in  four  families 
of  the  dragon  flies.  The  Aeschnidac  and  Gomphidae  have  a  flat 
mask  that  does  not  cover  the  face.  The  former  have  six-  or 
seven-jointed   slender  antennae;    the  latter,  four-jointed  stout 


Fig.  426. — Nymphs  of  the  dragon  flies:    a,  Anax;   b,  Aeschna;    c,  Boyeria. 
After  Needham. 

antennae.  The  Cordulegasteridae  and  the  Lihellulidae  have  a 
mask  that  is  spoon-shaped  and  that  covers  the  face.  The  teeth 
On  its  opposing  edges  in  the  former  are  large,  acute,  and  inter- 
locking;   in  the  latter  they  are  rounded.     Family  Aeschnidae 

includes  of  those  mentioned  above, 
Anax,  Aeschna,  and  Boyeria,  the 
nymphs  of  which  have  respectively 
three,  four,  and  five  pairs  of  lateral 
spines  on  the  sides  of  the  abdomen 
Fig.  427.— Head  of  horned     (Fig.  426).    Family  GompJiidae  includes 

da.ce, Semotilus atromaculatiis.        n  ,7  t^-      i    .  tt 

Progomplius,  Diastatomma,  Hagemus, 
Dromogomphus,  and  Gomphiis.  In  ProgompJius  the  middle  pair 
of  legs  are  set  closer  to  each  other  than  are  the  forelegs,  in  the 
others  at  least  as  far  apart  as  the  forelegs,  in  Hagenius  isLvthei 
apart.  Hagenius  also  has  more  than  four  pair  of  lateral  spines, 
the  others  not  over  four  pair.  The  tenth  or  last  abdominal 
segment   of   Diastatomma   narrows   posteriorly,    while    that   of 


282       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

Dromogomphus  and  Gomphns  has  its  sides  parallel.  Of  the  two 
latter  the  first  has  acute,  spiny-tipped  dorsal  hooks  on  the 
abdominal  segments,  while  in  Gomphiis  such  hooks  are  usually 


s^W"^- 


■4,V^*": 


*r? 


%>^ 


Fig.  428. — Red-bellied  dace,  Chrosomiis  erythrogaster 

absent  and  are  always  dull.     Family  Cordulegasteridae  includes 
only  the  genus  Cordulegaster.     The  rest  are  therefore  included 


Fig.  429. — Blunt-nosed  minnow,  Pimephales  notatus 

in  family  Lihellulidae,  the  nymphs  of  some  of  w^hich  are  not 
sufficiently  wxll  known  to  make  accurate  determination  possible. 
If  there  is  a  pyramidal 
horn  on  the  front  of 
the  head  and  a  small 
dorsal  hook  on  seg- 
ment ten,  the  nymph 
is  of  the  genus  Ma- 
cromia.     If  the  head 


Fig.  430. — Johnny  darter,  Boleosoma  nigrum 


bears  a  tubercle  on  each  side  and  segments  three  to  nine  bear 
dorsal  hooks,  the  nymph  is  that  of  Epicordidia.     If  the  lateral 


BROOK,  CREEK,  AND  RIVER 


283 


spines  of  segment  nine  are  sharp,  divergent,  and  longer  than 
the  appendages  of  segment  ten,  it  is  a  nymph  of  Tetragoneiiria; 
while  if  the  spines  of  nine  are 
incurved  and  not  longer  than 
the  appendages  of  ten,  the 
nymph  is  thsitoiSomatochlora. 
If  the  fish  of  the  streams 

are    studied,     again    we    find  Fig.  431.— Rainbow  darter,  £//zeo,y/owa 

certain    species  in   the    head-     coendemn,  two-thirds  natural  size. 

waters,  others  coming  in 
down  in  the  mid-course,  still 
others  not  appearing  until  the 
river  stage  is  reached,  and 
finally  some  largely  confined 
to  the  estuary.  Streams  that 
are  mere  brooks,  short  and 
small,  will  have  the  same  sort 

of   fish    that    are    found   near  Fig.  432.— Head  of  common  sucker, 

the  headwaters  of  the  larger     C^^^stofmis  commersonii,  one-third  natural 

size 

rivers.     The   horned   dace 

(Fig.  427)  is  apparently  the  fish  that  works  its  way  farthest 

upstream,  often  living  in  the  pools  of  brooks  that  otherwise 


'Sfjf^aiaaa 


Fig.  433. — Stone  roller,  Campostoma  anomalum 

have  dried  up.  The  red-bellied  dace  (Fig.  428)  and  the  black- 
nosed  dace  are  not  far  behind  it.  The  blunt-nosed  minnow 
(Fig.    429),  Johnny  darter  (Fig.  430),  and  the  rainbow  darter 


284       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Fig.  434. — Top  minnow,  Funduliis  dispar,  male 
and  female. 


(Fig.  431)  are  also  inhabitants  of  the  smaller  brooks,  while  the 
golden  shiner,  the  common  sucker  (Fig.  432),  and  the  chub  sucker 
(Fig.  192)  also  get  well  up  stream. 

The  following  may  be  considered  primarily  creek   fish:  the 
black  bullhead,  red  horse,  stone  roller  (Fig.  433),  common  shiner, 

river  chub,  common 
top  minnow,  Fundu- 
lus  dispar  (Fig.  434), 
fantailed  darter  (Fig. 
440).  While  those 
that  are  found  in  the 
rivers  are  the  mud  cat, 
the  stone  cat,  banded 
darter,  hog-nosed 
sucker  (Fig.  435), 
straw-colored  min- 
now (Fig.  436),redfin, 
red-faced  minnow,  gizzard  shad,  mud  minnow,  brook  silver- 
sides,  rock  bass  (Fig.  437), 
small-mouthed  black  bass, 
black  and  white  crappies  (Fig. 
438),  the  last  four  especially 
in  the  gravel-bottomed  pools. 
In  the  estuary  are  to  be 
found  those  fish  that  are 
ordinarily  lake-inhabiting 
forms  such  as  the  dogfish,  tad- 
pole cat,  buffalo,  grass  pike, 
bluegill,  pumpkin-seed,  large- 
mouthed    black     bass,    pike 

perch,  and  yellow  perch.  This  is,  of  course,  not  to  be  inter- 
preted as  meaning  that  the  brook  fish,  the  creek  fish,  or  the 
others  are  confined  to  one  particular  habitat,  but  merely  that 
if  one  makes  systematic  collections  they  will  be  captured  most 
frequently  in  the  situations  indicated. 


Fig.  435. — Head  of  hog  sucker,  Catos- 
tomus  nigricans,  one-half  natural  size. 


BROOK,  CREEK,  AND  RIVER 


285 


That  portion  of  the  stream  where  rapid  water  hurries  over 
stony  bottom  is  the  habitat  of  the  darters,  the  sucker-mouthed 


Fig.  436. — Straw-colored  minnow,  Notropis  hlennius 


Fig.  437. — Rock  bass,  Ambloplites  rupestris,  one-half  natural  size 


Fig.  438. — Black  crappie,  Pomoxis  sparoides,  one-third  natural  size 

minnow  (Fig.  439),  the  stone  roller,  the  hammerhead  sucker. 
The  rainbow  darter,  the  fantail,  black-sided  (Fig.  441),  sharp- 


286        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

headed  (Fig.  442),  banded,  and  Johnny  darter  are  all  able  by 
their  large  pectoral  and  anal  fins  to  hold  themselves  among  the 
stones  in  the  swift  current  and  search  under  them  with  their 
pointed  heads  for  insect  larvae.     The  sucker-mouthed  minnow 


Fig.  439. — Sucker-mouthed  minnow,  Phenacohius  mirahiUs 

has   similar   feeding   habits.     The   stone   roller,   as    the   name 
indicates,  moves  the  smaller  stones  in  his  efforts  to  nibble  off 

the  slime,  while  the  hammer- 
head sucker  can  dislodge 
quite  good-sized  stones  in 
his  effort  to  locate  hiding 
Fig.  440.— Fan-taUed  darter,  £/Aeo5/owia  animals.  On  the  other 
flahellare,  two-thirds  natural  size.  ^^^^^  ^^^^^  ^^^  ^^^^^.^  ^^^ 

found  in  the  sluggish  waters  over  mud  bottom.     Such  are  the 
black  bullhead,  hog  sucker,  and  golden  shiner. 


Fig.  441. — Black-sided  darter,  Hadroptenis  aspro  * 

No  association  contains  more  remarkably  adapted  animals 
than  this  lotic  or  Hydropsyche  association.  The  net  building 
caddis  fly  (Hydropsyche)  (Fig.  443)  forms  a  cornucopia-shaped 
tube  open  at  both  ends  with  the  large  flaring  end  upstream, 


BROOK,  CREEK,  AND  RIVER  287 

This  is  attached  to  the  rocks  on  the  bottom.  The  large  end  of 
the  tube  is  covered  with  a  cup-shaped  net  spun  of  silken  strands. 
The  larva  lies  at  one  side  of  the  net  and  picks  off  the  small 
animals  and  plants  the  current  brings  down.  Not  infrequently 
the  entire  upper  surface  of  the  stones  on  the  bottom  will  be 
covered  with  these  net  tubes  of  this  larva.  Another  caddis- 
fly  larva,  Helicopsyche,  has  a  coiled  tube  built  of  sand  grains 
(Fig.  444)  that  appears  like  a  small  snail  shell.  This  lives  in  mod- 
erately rapid  water  of  the  large  creeks  where  the  bottom  is  pebbly. 
It  attaches  to  the  rocks.  The  larva  of  the  black  fly,  Simulium, 
is  universally  present  in  the  rapid  water  running  over  stones 
from  the  merest  trickle  in  the  tiny  runnel  way  down  stream  as 


Fig.  442. — Sharp-headed  darter,  Hadroptcrus  phoxoccphaliis 

long  as  rocks  on  the  bottom  afford  attachment.  The  larvae 
appear  like  black,  squirming,  short  worms  with  brushes  of  bristles 
at  the  free  end,  by  means  of  which  they  catch  the  tiny  animals 
and  plants  floating  in  the  current.  They  are  so  numerous  as  to 
make  great  patches  on  the  rocks.  Each  larva  is  attached  at 
one  end  by  a  sucker  but  can  let  go  at  will  when  it  spins  a  silken 
strand,  at  the  end  of  which  it  dangles  in  the  water,  seeking  new 
feeding  ground.  The  adults  are  the  pestiferous  tiny  flies  that 
swarm  about  the  head  of  the  fishermen  or  the  udder  of  browsing 
cattle  and  take  bloody  toll.  Under  the  stones  one  finds  blood- 
worms, larvae  of  midges  of  genus  Chironomus,  stone-fly  nymphs 
(Ferla)y  damsel-fly  nymphs  {Argiapntrida),  May-fly  nymphs 
{Siphlurus  allernatus) ,  the  larva  of  a  water  beetle  (Fig.  446)  so 
flattened  and  rounded  it  is  called  the  water  penny  {Psephenus 
lecontei).  These  nymphs  in  the  rapidly  running  water  have 
head,  body,  and  limbs  all  flattened  to  offer  the  least  possible 


288       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


resistance  to  the  water,  and  many  of  them  have  specially  devel- 
oped suckers,  by  means  of  which  they  attach  to  the  rock.  The 
water  penny  (Fig.  445)  is  so  altered  by  its  adaptation  to  its 
environment  that  one  would  never  take  it  at  first  sight  for  a 
beetle  larva. 

The  snail,  Goniobasis  livescens,  lives  in  the  rocky  rapids, 
dozens  of  them  often  on  a  single  bowlder,  clinging  on  by  their 
strong  muscular  foot,  feeding  on  the  microscopic  plants  that 


Figs.  443-447:  Fig.  443. — Net-building  caddis-fly  larva,  Hydropsychc,  in  its 
tube  (above);  front  view  of  tube  (below),  enlarged;  Fig.  444. — Coiled  tube  of 
larva  of  caddis-fly,  Hdico psyche,  enlarged;  Fig.  445. — Water  penny,  larva  of  446; 
Fig.   446. — Brook   beetle,   Psephenus  lecontci;    Fig.    447. — A    common    rotifer. 


much  enlarged. 


form  the  slimy  layer  of  green  scum  on  the  rocks.  The  liberty 
cap  snail,  Ancylus,  whose  coiled  shell  has  been  reduced  to  a 
broad,  low  cone,  is  fairly  abundant  in  the  stony  rapids  of  the 
brooks. 

Pleurocera  elevatum  is  found  where  the  current  is  not  so  very 
strong.  It  often  prefers  the  gravelly  margins  of  the  stream. 
The  crayfish,  Caniharus  virilis,  is  found  hiding  under  the  stones, 
very  commonly. 


BROOK,  CREEK,  AND  RIVER  289 

In  the  moderately  rapid  waters  with  sandy  or  gravelly 
bottom  will  be  found  Campelonia  suhsolidiim  and  C.  integrum, 
good-sized  snails.  These  spots  are  the  habitat  of  the  clams 
already  mentioned.  It  is  in  the  larger  rivers  that  the  good-sized 
specie  occur  abundantly,  forming  mussel  beds  on  the  sand  bars. 
The  clam  lies  buried  in  the  sand  or  silt  with  only  the  posterior 
portion  of  the  shell  protruding.  Out  of  this  end  stick  the 
siphon  tubes  which  take  in  the  water  containing  the  tiny 
animals  and  plants  (plancton)  on  which  the  clam  feeds.  It  is 
from  the  thick  shells  of  the  larger  species  that  the  pearl  buttons 
are  stamped. 

In  the  quieter  stretches  of  the  stream,  where  the  bottom  is 

muddy,  w^ill  be  found  the  burrowing  May-fly  nymphs  of  genus 

Hexagenia,  the  fish  and  dragon-fly  nymphs  already  noted,  and 

.a  number  of  forms  identical  with  those  of  ponds.     Just  at  the 

^margin  of  the  quiet  waters,  where  the  current  goes  swiftly  by, 

rwill  be  found  the  May-fly  nymph,  Chirotenetes  siccus. 

The  plant  life  along  the  shore  and  in  the  bed  of  the  stream 
is  in  general  appearance  very  like  that  in  similar  situations  in 
the  ponds  and  lakes,  though  the  constituent  species  may  be 
quite  different.  Attached  to  the  rocks  and  logs  in  the  stream 
bed  are  numerous  filamentous  algae  and  some  water  mosses. 
Stones  and  logs  are  found,  slippery  with  the  mucus  secreted  by 
diatoms  or  other  algae  that  coat  their  surfaces  with  a  dense 
layer  of  plant  life,  and  the  stream  is  often  choked  in  its  quieter 
stretches  with  submerged  plants  similar  to  those  of  the  ponds, 
Myriophylum,  Utricularia,  Elodea,  Vallisjieria,  Cera.topJiyllum,  etc. 
In  quiet  stretches  pond  lilies  are  common.  The  shores  are  lined 
with  zones  of  plants,  rushes,  cat-tails,  arrow  root,  sedges,  and 
grasses. 

These  relatively  quiet  marginal  areas  are  the  breeding-places 
for  an  abundant  plant  and  animal  life,  largely  minute  forms,  the 
overflow  of  which  is  carried  downstream  in  the  current  as  the 
plancton.  This  consists  largely  of  microscopic  plants,  diatoms, 
desmids,  and  other  single-celled  forms,  of  some  filamentous  types, 


290       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

of  many  animals  like  the  protozoa,  rotifers  (Fig.  447),  and  small 
crustaceans.  The  waters  of  midstream  are  teeming  with  this 
floating  population,  of  which  one  is  not  aware  until  he  strains 
it  out  with  a  fine  net.  Kofoid  found  in  the  Illinois  River  at 
Urbana  almost  five  milhon  organisms  to  the  quart,  a  million  of 
which  were  animals.  He  estimates  the  total  plancton  carried 
down   by   the   river   per    year   at   more   than   two   and   one 


Fig.  448. — Valley  of  lower  Galien  River,  New  Buffalo,  ISIichigan.     Note  plant 


zonation  in  foreground. 


quarter  million  cubic  feet  of  solid  organisms.  Certain  flagellates, 
ciliated  forms  .like  Vorticella,  and  the  shell-bearing  rhizopods, 
Difflugia  and  Arcella,  are  among  the  commoner  protozoa. 
Daphne,  Bosmina,  Aero  per  us,  Leptohora,  are  common  cladoceran 
crustaceans,  while  Cyclops,  Diapotamiis,  and  Canthocampus  are 
the  customary  copepods.  A  very  transparent  midge  larva, 
Corethra,  is  sometimes  very  abundant.  It  is  nearly  an  inch 
long  and  so  transparent  that  the  internal  organs  are  plainly 
visible  as  if  it  w^ere  made  of  glass.  The  crustaceans  of  the 
plancton   are   the   staple   article   of   diet   for  all  of  the  small 


BROOK,  CREEK,  AND  RIVER  291 

carnivorous  fish  of  the  stream.  The  crustaceans,  in  turn,  feed 
upon  the  smaller  organisms  of  the  plancton,  both  plant  and 
animal. 

The  first  animal  to  appear  in  intermittent  streams,  even  when 
it  is  a  mere  trickle,  is  the  larva  of  the  black  fly.  Along  with  this 
are  to  be  found  larvae  of  May  flies,  under  the  stones,  and  caddis 
worms  in  their  irregular  tubes  formed  of  bits  of  stone  (Rhynco- 
philidae) . 

In  the  pools  of  such  intermittent  streams  are  found  in  the 
spring  crayfish  (Cambarus  diogenes)  that  dig  in  and  live  in  their 
burrows  as  the  temporary  pools  dry  out.  They  come  out  at 
night  to  secure  their  food.  As  the  pools  become  larger  and 
more  permanent,  Cambarus  virilis  and  C.  propinqims  replace  the 
burrowing  crayfish.  Gammarus  fasciatiis  and  Asellus  are  added 
to  the  crustacean  population.  Water  striders,  back-swimmers, 
and  water  boatmen  appear.  The  diving  beetles,  Hydroponis  and 
A  gabies,  are  found.  Burrowing  dragon-fly  nymphs  inhabit  the 
pools,  and  the  adults  fly  over  their  surfaces  {Aeschna  constricta 
and  Cordulegaster  obliquus). 

The  first  fish  to  appear  is  the  horned  dace  {Semotilus  atroma- 
culatus).  It  swims  away  upstream  to  deposit  its  eggs,  so  the 
young  are  common  in  these  temporary  pools  and  often  die  in 
large  numbers  as  they  dry  out.  The  red-belHed  dace  {Chrosomiis 
erythrogaster)  is  Kkely  to  get  almost  as  far  upstream,  but  breeds 
only  in  pebbly  and  sandy  bottom.  It,  too,  is  found  in  the  tem- 
porary pools. 

In  the  spring-fed  brooks  the  characteristic  vegetation  is  the 
water  cress.  Black-fly  larvae  are  present,  as  also  the  same 
benders,  crayfishes  and  beetles  mentioned  above.  In  addition, 
the  net-building  caddis  fly  {Hydro psyche)  is  found.  The  brook 
beetle,  Elmis  fastiditus,  is  very  characteristic.  The  spring-fed 
brooks  in  our  locaHty  are  very  short,  usually  joining  some  larger 
stream  quite  promptly.  In  these  springs  and  brooks  such 
planarians  as  Dendrocoelum  and  Planaria  dorotocephala  are 
abundant. 


292       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

As  one  proceeds  downstream  to  a  point  where  the  river 
has  cut  down  nearly  to  the  level  of  the  body  of  water  into 
which  it  flows  it  is  prone  to  become  sluggish,  choke  its  own 
mouth  with  sand  or  mud  bars,  back  up  and  spread  out  over  a  wide 
area  of  its  lower  flood  plain,  and  so  develop  an  estuary.  A  very 
good  example  of  this  is  seen  above  the  mouth  of  the  Galien  River 
at  New  Buffalo,  Michigan  (Fig.  448).  Conditions  are  practically 
those  of  the  filling  lake  or  pond.  The  zones  of  plants  and  animals 
are  well  developed  and  occur  in  the  same  order  as  already 
discussed  in  the  chapter  on  the  filling  pond. 


CHAPTER  XIV 
SOME  SOURCES  OF  OUR  FAUNA  AND  FLORA 

HE  preceding  chapters,  if  they  have 
accomplished  their  purpose,  have  given 
the  attentive  reader  the  conception, 
based  on  a  good  deal  of  detailed  evi- 
dence, that  plants  and  animals  are  not 
jumbled  together  in  the  outdoors  in 
chance  assortments,  but  are  grouped  in 
very  definite  associations,  quite  as  clear 
cut  as  are  human  societies.  Indeed,  sociology  may  be  regarded 
as  the  science  of  human  ecology.  This  notion  gives  added  zest 
to  one's  excursions  afield.  You  learn  not  only  to  recognize  the 
common-place  forms  but  to  study  their  groupings  and  to  give 
attention  to  those  structural  and  functional  adaptations  by  which 
organisms  are  fitted  to  a  specific  environment.  We  have  found 
structurally  very  unlike  forms,  both  plant  and  animal,  closely 
associated,  and  very  like  forms  completely  separated.  The 
rapids  society  of  the  stream  is  made  up  of  fish,  insect  larvae  of 
many  orders,  crustaceans,  leeches,  and  mollusks,  a  strangely 
assorted  family.  On  the  dunes  the  closely  related  tiger  beetles, 
all  predatory  forms  very  similar  in  habit,  were  found  each  in  its 
particular  zone.  Ecological  groupings  of  plants  and  animals 
will  often  or  usually  cut  across  taxonomic  groupings. 

Thus  far,  however,  we  have  considered  the  matter  from  the 
static  point  of  view.  We  have  considered  the  associations  of 
plants  and  animals  as  they  are.  There  is  a  dynamic  side.  We 
need  to  consider  how  they  have  come  to  be.  The  present 
is  the  outcome  of  an  eventful  past  and  is  to  be  explained  as 
the  resultant  of  many  forces  operating  through  long  periods 
of  time. 


'>C\7 


294       ^  NATURALIST  IN  THE  GREAT  LAKES  REGION 

Without  going  back  unduly  into  the  past,  it  is  very  evident 
that  when  the  last  glacial  advance  slowly  came  on  and  buried 
the  Great  Lakes  region  almost  in  its  entirety  under  thousands  of 
feet  of  ice,  the  plant  and  animal  Hfe  existent  here  before  the 
advance  began  must  have  been  obHterated,  except  in  so  far  as 
it  could  retreat  southward  into  congenial  territory.  Moreover, 
there  must  have  been  a  complete  change  in  the  fauna  and  flora 
even  before  the  glacier  arrived.  For  as  it  progressed  there 
preceded  it  a  change  in  cKmate.  The  rigors  of  the  winters 
increased,  the  summers  became  brief  and  cool.  Many  of  the 
plants  and  animals  flourishing  here  before  the  ice  sheet  began  its 
southward  movement  must  have  been  driven  out  and  replaced 
with  forms  more  characteristic  of  the  north.  Evergreens  took 
the  place  of  the  deciduous  forests,  and  the  animals  changed 
accordingly.  As  the  glacier  approached  still  nearer,  the  conifer- 
ous forests  extended  farther  south,  while  here  trees  were  becoming 
dwarfed.  Then  this  region  became  treeless,  and  tundras  covered 
with  hardy  grasses,  mosses,  and  lichens  occupied  it,  similar  to  those 
existent  in  the  far  north  on  the  border  of  the  regions  of  perpetual 
snow.  Finally  this  tundra  region  moved  south,  and  the  glacier 
itself  came  on.  Probably  neither  the  tundra  zone  bordering  the 
glacier  nor  the  coniferous  forest  zone  beyond  it  were  very  wide 
when  the  glacier  reached  its  maximum  extension,  for  it  was  melt- 
ing along  its  front,  so  the  climate  there  could  not  have  been  very 
rigorous.  The  deciduous  forest  probably  covered  much  of  the 
southeastern  portion  of  the  continent  and  the  arid  plains  and 
short  grass  regions  much  of  the  southwestern  portions  as  now. 

When  the  last  glacial  period  was  passing  off  and  the  great 
ice  sheet  was  beating  a  slow  retreat,  the  land,  with  topography 
much  changed,  was  open  to  plant  and  animal  occupation.  The 
great  tundras,  the  areas  of  stnnted  trees,  and  the  coniferous 
forests  largely  followed  the  glacier  northward,  leaving  a  few 
scattered  remnants  here  and  there.  The  climate  of  our  region 
again  became  congenisil  to  the  deciduous  forests,  the  prairie- 
plants,  and  their  accompanying  animals. 


SOME  SOURCES  OF  OUR  FAUNA  AND  FLORA  295 

Whence  then  came  the  plant  and  animal  immigrants  that 
replenished  our  barren  region?  Briefly  stated,  the  facts  are 
these.  Certain  elements  of  our  present  fauna  and  flora  are 
relics  of  the  tundras  and  the  coniferous  forests.  In  addition,  the 
sterile  land  uncovered  by  the  retreating  glacier  was  gradually 
repopulated  by  immigrants  from  at  least  three  centers,  one  an 
arid  region  in  the  southwest  with  whose  fauna  and  flora  ours  has 
many  afflnities.  A  second  center  was  in  the  southeast;  from  it, 
for  example,  have  come  most  of  our  deciduous  forest  trees  and  our 
river  clams.  The  third  region  from  which  ours  has  received  con- 
tributions is  the  Atlantic  Coast  plain.  Many  animals  and  plants 
of  the  shores  of  the  Great  Lakes  are  identical  with  those  of  the 
eastern  seacoast.  And  finally  there  is  a  very  perplexing  factor  in 
that  the  only  close  relatives  of  certain  of  our  plants  and  animals  to 
be  found  anywhere  in  the  world  are  along  the  eastern  coast  of  Asia. 

There  are  no  remnants  of  the  tundra  formation  in  the  immedi- 
ate vicinity  of  Chicago,  for  such  exist  in  eastern  North  America 
only  in  isolated  patches  on  the  mountain  tops.  Such  are  found 
in  the  Great  Lakes  region  on  the  high  hills  of  northern  Wisconsin 
and  Michigan.  As  exa.mples  of  such  forms  may  be  mentioned 
the  dwarf  grass,  Agropyron  biflorum,  the  herbaceous  willow,  Salix 
herbacea,  a  very  low  form  with  an  underground  stem  that  lies  in 
the  wet  mosses,  Rhododendron  lapponicum,  Arctostapliylos  alpina, 
some  dwarf  blueberries,  Vaccinum  oliginosum  and  V.  caespitosum, 
mosses  and  lichens  such  as  the  Cladonia  rangiferina. 

There  are,  in  the  pine  association  of  the  Dunes,  as  already 
noted,  extensive  areas  with  a  distinct  boreal  character.  Here 
flourish  Pinus  strobus,  P.  Banksiana,  together  with  the  arbor 
vita,  low  and  spreading  junipers,  such  boreal  shrubs  as  prince's 
pine,  shinleaf,  arbutus,  northern  herbs  like  star  flower,  false 
lily-of-the-valley,  etc.  There  are  scattered  remnants  of  this 
coniferous  society  on  rocky  hills  elsewhere,  particularly  on  their 
dry  crests  and  cold  northern  slopes.  Associated  at  times  with 
these  plants  in  the  Dunes,  but  elsewhere  in  our  region  quite 
isolated,  is  another  subarctic  formation,  the  sphagnum-tamarack 


296        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

bog  society.  This  and  the  pine  association,  found  in  our  region 
as  more  or  less  isolated  islands  in  the  midst  of  the  prevalent 
oak-hickory  society,  are,  farther  north,  the  prevalent  thing. 
The  sphagnum  bogs  cover  wide  areas  and  have  their  maximum 
development  in  a  region  extending  from  north  of  the  Gulf  of 
St.  Lawrence  to  northern  New  England  in  the  East,  thence 
west,  spreading  from  mid-Lake  Michigan  shores  to  Hudson 
Bay  and  then  northwest  into  Saskatchewan.  There  can  be  no 
doubt  that  this  bog  society  like  the  pine  association  invaded 
our  region  in  advance  of  the  glacier  and  followed  it  back  in  its 
retreat,  leaving  the  isolated  patches  in  favorable  localities  to 
continue  to  the  present,  defying  the  encroachments  of  the  plants 
and  animals  that  later  came  to  occupy  most  of  the  region.  There 
is  therefore  no  gradual  transition  from  the  sphagnum-tamarack 
bog  society  to  the  surrounding  societies,  but  an  abrupt  break 
between  the  two,  for  this  northern  invader  is  surrounded  by 
still  later  arrivals  with  which  it  has  no  genetic  continuity.  In 
the  north  it  leads  to  the  coniferous  forest,  but  here  the  conif- 
erous forest  itself  is  at  best  struggling  to  maintain  a  none  too 
secure  footing.  The  coniferous  forest  farther  north  leads  on  to 
the  hardwood  climax  forest,  so  that  the  transition  from  the  pine 
association  here  to  the  black  oak  association  is  a  relationship 
that  is  not  strained.  There  seems  to  be  some  evidence,  as  at 
Cedar  Lake,  that  the  tamarack  bog  does  still  develop  in  this 
region.  Young  tamaracks  are  appearing  in  the  sphagnum  bog 
there  and  are  pushing  farther  out  into  it. 

How  these  northern  elements  came  into  our  fauna  and  flora 
is  quite  evident.  The  glacier  forced  them  south  and  the  rising 
temperature  in  the  south  as  the  glacier  retreated  forced  them  to 
migrate  north  again  or  suffer  extinction,  except  as  relics  survive 
in  limited  favorable  localities.  But  what  has  forced  the  invasion 
into  our  region,  since  the  glacier  left  it  largely  bare,  of  forms 
from  the  deciduous  forest  center  in  the  southeastern  part  of  the 
continent,  the  prairie  and  desert  regions  of  the  Southwest,  or 
the  Atlantic  seaboard  ? 


SOME  SOURCES  OF  OUR  FAUNA  AND  FLORA  297 

The  driving  power  back  of  these  movements  is  the  urge  of 
rapidly  multiplying  life.  Each  species  tends  to  fill  its  habitat 
full  to  overflowing.  So  prolific  are  living  things  that  the  pressure 
to  move  out  into  adjacent  territory  is  only  checked  by  impassable 
barriers  that  raise  the  swelHng  tide  until  some  outlet  is  found  or 
multiplication  is  offset  by  the  high  mortality  of  keen  competi- 
tion. So  quiet  and  unobtrusive  is  the  life  of  the  ordinary  plant 
and  animal  that  we  humans  find  it  difficult  to  realize  how  keen 
is  the  struggle  for  existence  or  with  what  celerity  any  new 
territory  is  occupied.  There  is  no  roar  of  hostile  guns  along  the 
battle-line  of  opposing  animal  and  plant  interests,  no  press 
dispatches  tell  of  starving  thousands,  no  blare  of  trumpets  or 
floating  banners  mark  the  progress  of  quiet  invasion.  But  there 
is,  nevertheless,  tremendous  activity.  Reproduction  is  at  a 
geometrical  rate;  that  is,  a  pair  does  not  give  rise  to  another 
pair  merely,  but  to  a  litter,  a  swarm,  a  horde.  A  single  female 
codfish  lays  five  milHon  eggs  at  one  spawning.  A  pair  of  potato 
beetles  would  produce  in  one  season  a  progeny  of  sixty  million, 
if  all  their  offspring  and  their  offspring,  too,  lived  unmolested. 
''The  descendants  of  a  common  housefly  would  in  the  same 
time — six  generations  of  about  three  weeks  each — occupy  a  space 
of  something  Hke  a  quarter  of  a  million  cubic  feet,  allowing  two 
hundred  thousand  flies  to  a  cubic  foot.  An  oyster  may  have 
sixty  million  eggs  and  the  average  American  yield  is  sixteen 
millions.  If  all  the  progeny  of  one  oyster  survived  and  multi- 
plied, and  so  on  until  there  were  great-great-grandchildren,  these 
would  number  sixty-six  with  thirty-three  noughts  after  it,  and 
the  heap  of  shehs  would  be  eight  times  the  size  of  the  earth! 
Of  course  none  of  these  things  happen  because  of  the  checks 
imposed  by  the  struggle  for  existence.  Yet,  every  now  and 
then,  as  man  knows  to  his  cost,  a  removal  or  diminution  of  the 
natural  checks  aUows  the  potential  productivity  to  assert  itself 
for  a  short  time  or  within  a  hmited  area.  The  river  of  life  some- 
times does  overflow  its  banks,  as  it  always  tends  to  do,  and  the 
resulting  flood  is  called  a  plague ''  (Thomson,  The  Wonder  of  Life) . 


298       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

Begin  with  a  single  dandelion  plant  bearing  a  single  blossom 
cluster  in  the  ^ear — a  slander  on  the  enterprising  dandelion — ■ 
that  gives  rise  to  a  hundred  seeds.  Let  these  find  lodgment 
and  next  year  produce  plants  that  each  grow  a  single  blossom 
cluster  that  produces  one  hundred  seeds,  and  so  on.  It  will  be 
a  matter  of  less  than  ten  years  before  there  are  enough  dande- 
hon  plants  to  cover  every  foot  of  land  upon  the  face  of  the  earth. 
Or  consider  the  coyote  that  brings  into  being  a  litter  of  eight 
or  nine  pups  at  a  time.  Suppose  these  are  half  male  and  half 
female  and  require  two  years  to  reach  sufficient  maturity  to 
breed.  Let  the  breeding  life  be  only  five  years,  and  if  nothing 
interfered  with  the  multiplication  of  a  single  pair  and  that  of 
their  offspring  inside  of  half  a  century  there  would  be  a  coyote 
for  every  square  foot  of  earth.  The  rancher  who  has  tried  to 
exterminate  his  coyote  neighbors,  or  the  householder  who  tries 
to  keep  his  lawn  free  from  dandehons,  knows  that  the  possibili- 
ties are  not  overdrawn. 

As  a  result  of  such  astounding  fertility,  usually  more  or  less 
held  in  check  by  enemies  that  prey  upon  the  offspring,  there  is 
every  now  and  then  an  overflow  of  a  species  from  its  habitat 
into  the  surrounding  territory,  where  if  conditions  are  favorable 
it  permanently  establishes  itself.  The  Rocky  Mountain  locusts 
have  repeatedly  appeared  in  great  hordes  in  the  plains  states 
near  the  mountains,  a  devastating  army  that  comes  in  clouds, 
darkening  the  sun,  that  leaves  cornfields  as  barren  wastes  within 
a  few  hours  after  ahghting  upon  them,  plagues  of  locusts  that 
have  inflicted  millions  of  dollars  of  damage  on  crops  covering 
wide  areas.  The  Lapland  leming  is  a  small  rodent  which  every 
ten  or  fifteen  years  moves  out  from  its  home  through  surrounding 
regions  in  vast  numbers,  devouring  every  green  thing  and  usually 
being  devoured  by  hawks,  owls,  foxes,  and  other  species  of  preda- 
tory animals  that  follow  in  its  wake  in  numbers.  In  the 
Farmers^  Bulletin  No.  jj2,  United  States  Department  of  Agri- 
culture, is  described  a  plague  of  mice  in  the  Humboldt  Valley, 
Nevada,  from  which  a  few  sentences  are  quoted. 


SOME  SOURCES  OF  OUR  FAUNA  AND  FLORA 


299 


Extensive  ravages  first  occurred  above  and  about  Lovelocks.  In 
May,  1907,  fields  on  the  Rogers  ranch,  5  miles  below  Lovelocks,  were  invaded 
from  lands  farther  up  the  valley,  the  progress  of  the  mice  being  plainly 
marked,  as  the  fields  above  the  Rogers  ranch  suffered  first.  The  move- 
ment of  this  great  body  of  mice,  it  should  be  noted,  was  a  gradual,  scattering 
progression,  first  by  a  few  and  later  by  increasing  numbers,  untU  the  greater 

part  had  moved  to  fresh  fields By  October,  1907,  a  large  part  of 

the  cultivated  lands  in  this  district  had  been  overrun  by  vast  numbers  of 
mice The  height  of  the  abundance  was  reached  in  November,  when 


Fig.  449. — Map  of  potato  beetle  invasion,  with  dates  of  arrival  at  some 
localities.     After  Tower. 

it  was  estimated  that  on  many  large  ranches  there  were  8,000  to  12,000 
mice  to  each  acre.  The  fields  were  riddled  by  their  holes,  which  were 
scarcely  a  step  apart,  and  over  large  areas  averaged  150  to  175  to  the  square 
rod.     Ditch  embankments  were  honeycombed,  and  the  scene  was  one  of 

desolation By  November  they  had  destroyed  so  large  a  percentage 

of  the  plants  that  many  fields  were  plowed  up  as  hopelessly  ruined 

By  January,  1908,  in  fields  where  the  mice  had  existed  by  thousands  the 
previous  summer  and  fall,  comparatively  few,  possibly  200  to  500  to  each 
acre,  remained.  The  border  of  the  destroyed  district  was  about  6  miles 
below  Lovelocks,  and  the  mice  were  gradually  moving  down  the  valley. 

The  exact  data  regarding  such  invasions  of  adjacent  territory 
by  animals  and  plants  are,  as  a  rule,  only  available  when  the 


300       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

invading  forms  affect  man's  crops  or  his  domestic  animals. 
When  about  the  middle  of  the  last  century  settlers  pushing  west- 
ward brought  the  fields  of  cultivated  potatoes  to  the  edge  of  the 
habitat  of  the  Colorado  potato  beetle,  there  feeding  on  wild 
species  of  the  potato  family,  the  eastward  movement  of  this 
animal  began.  The  progress  of  its  invasion  and  the  routes 
followed  can  be  seen  on  the  accompanying  map  (Fig.  449). 
Similarly  the  cotton-boll  weevil,  which  came  out  of  Mexico  to 
invade  the  United  States,  is  rapidly  spreading  all  over  the  South 
where  cotton  is  a  crop.  Its  advance  is  shown  in  the  accompany- 
ing map  (Fig.  450).  Jimson  weed  (a  shortening  of  the  original 
name,  Jamestown  weed)  was  introduced  from  the  Old  World  into 
this  country  at  Jamestown  in  colonial  days,  from  whence  it  has 
spread  all  over  the  Eastern  United  States.  Russian  thistle, 
introduced  into  this  country  by  immigrants  in  wheat  seed  planted 
in  North  Dakota  in  1873,  ^^^  since  then  spread  pretty  much 
all  over  this  country  and  much  of  Canada  east  of  the  Rockies. 
This  insurgency  of  living  things,  impelKng  them  to  seek  new 
fields  to  conquer,  soon  repopulated,  from  the  three  centers  named, 
the  territory  laid  waste  by  the  glacier.  Southeastern  United 
States  seems  to  be  the  distribution  center  from  which  have  come 
most  of  our  deciduous  forest  trees,  the  river  clams,  such  snails 
as  the  Pleiiroceridae  and  Viviparidae,  most  crayfish,  and  a  large 
share  of  our  fish.  Undoubtedly  many  other  forms  have  also 
come  from  this  same  center  concerning  whose  movements  we 
have  little  or  no  data.  This  southeastern  center  is  particularly 
rich  in  species  and  varieties  of  the  forms  mentioned.  They  there 
attain  their  maximum  size.  From  this  center  the  connecting 
rivers  and  their  valleys  afford  easy  highways  of  invasion.  All 
of  which  are  good  criteria  for  determining  centers  of  immigra- 
tion. A  map  of  North  America  on  which  there  is  drawn  in 
outline  the  present  range  of  a  number  of  our  important  trees 
shows  at  a  glance  that  this  southeastern  area  is  a  center  for  all 
(Fig.  451).  There  are  omitted  frorn  this  the  evergreens  and 
such  deciduous  trees  as  evidently  belong  to  the  northern  forest. 


SOME  SOURCES  OF  OUR  FAUNA  AND  FLORA  301 


o 


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o 

a, 

03 


o 


302        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

There  are  more  species  of  fresh-water  clams  in  this  south- 
eastern area,  with  Chattanooga  as  its  approximate  center,  than 
in  all  the  rest  of  the  world.  The  number  of  species  decrease  as 
you  go  farther  and  farther  away  from  this  center.  Thus,  while 
Maine  has  only  lo  species  of  Uniojiidae,  Michigan,  much  nearer 


Fig.  451.— Distribution  of  certain  typical  deciduous  trees 

along  the  migration  route,  has  61,  Ilhnois  SS,  and  Alabama  256. 
Of  the  Pleuroceridae  Maine  has  none,  Michigan  10,  IlHnois  28, 
while  Alabama  has  302.  Bryant  Walker  {Distrihution  of  the 
Unionidae  in  Michigan,  Michigan  Academy  of  Science,  1898) 
considers  that  the  IVIichigan  Unionidae  are  almost  entirely 
Mississippian,  only  two  species,  Anadonta  fragilis  and  Unio 
complanatiis  having  come  from  the  east.     These  clams  must 


SOME  SOURCES  OF  OUR  FAUNA  AND  FLORA  303 


have  reached  Michigan  while  Lake  Chicago  and  its  successors, 
drained  by  way  of  the  Illinois  and  the  Wabash,  since  now  all 
the  streams  of  IMichigan  are  part  of  the  St.  Lawrence  drainage 
system.  That  some  of  the  more  hardy  of  the  clams  did  follow 
the  glacial  retreat  closely  is  evidenced  by  the  fact  that  their 
shells  are  found  in  undisturbed  beaches  of  the  post-glacial  lakes. 

Of  the  150  species  of  fresh-water  fishes  found  in  Illinois  that 
are  native  to  the  state  ''there  are  58  species  of  the  east  Gulf  and 
Florida  district"  (Forbes  and  Richardson,  The  Fishes  of  Illinois, 
*'  Natural  History  Survey  of  Illinois  ") .  From  the  WTst  Gulf  and 
Rio  Grande  region  there  are  forty-seven  species  of  fish  (same 
authority).  From  this  same  southwestern  center  come  such 
animals  as  our  pocket  gopher,  rattlesnake,  six-lined  lizard;  and 
such  plants  as  the  dune  cactus,  Andropogon  scoparius,  A.fur- 
catus,  Panicum  praecocius,  Schedomiardus  paniculatus,  Cyperus 
aristatus,  C.  acuminatiis,  Eleocharis  tenuis,  Carex  trlbuloides, 
Asclepias  tnherosa,  Silphium  terehinthinaceum,  Rudheckia  hirta, 
all  plants  that  find  congenial  habitat  in  the  dry  sandy  areas  or 
the  dry  prairies. 

From  the  Atlantic  coastal  plain  region  our  fauna  and  flora 
have  received  many  contributions.  It  will  be  recalled  that 
during  the  retreat  of  the  glacier  our  Great  Lakes  region  was  in 
much  more  direct  communication  with  the  Atlantic  seaboard 
than  it  is  at  present  (Fig.  52).  There  are  fifty- three  of  the  fish 
of  Illinois  that  have  come  from  Quebec  and  the  New  England 
region.  As  already  noted,  some  of  our  clams  come  from  this 
eastern  center,  possibly  originally  emanating  from  the  south- 
eastern center,  but  if  so  migrating  to  our  region  by  way  of  the 
coastal  plain.  A  large  number  of  the  plants  found  along  the 
shores  of  the  Great  Lakes  seem  to  have  come  from  this  source. 
A  few  may  be  mentioned,  such  as  Panicum  verrucosimi,  P.  oligo- 
santhes,  Aristida  tuberculosa,  Ammophila  arenaria  (marram 
grass),  Eleocharis  melanocarpa,  Psilocarya  scirpoides,  Fuirena 
squarrosa,  Cakile  edentulata  (sea  rocket),  Euphorbia  polygonifolia 
(seaside  spurge),  Xanthium  echinatum  (cocklebur). 


304       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 

Finally  a  great  many  of  our  plants  and  animals  are  common 
to  Northern  Eurasia  and  Northern  North  America,  while  some 
of  ours  have  their  nearest  relatives  along  the  eastern  edge  of 
Asia.  Our  common  bluebird  (Sialia  sialis)  has  an  isolated  close 
relative  {Sialia  codicolor)  in  Eastern  Asia.  Our  spoonbill  and 
carp  sucker,  the  former  a  peculiar  mud-eating  fish,  have  each 
a  near  relative  in  China.  Our  crayfishes  are  more  nearly  related 
to  those  of  Eastern  Asia  than  to  the  species  of  our  own  Pacific 
Coast  or  of  Eastern  Europe.  Our  dragon  flies,  Hageniiis  and 
Boyeria,  have  close  relatives  in  Eastern  Asia.  The  tulip  tree, 
sweet  gum,  and  sour  gum  all  belong  to  genera  found  nowhere 
else  in  the  world  except  Eastern  North  America  and  Eastern  Asia. 

Confining  our  attention  to  the  ferns,  horsetails,  and  club 
mosses,  the  following  are  common  to  Europe  and  North  America, 
including  our  Great  Lakes  region :  Poly  podium  vulgare,  Aspidiiwi 
cristatum,  A.  spinulosum,  Osmuiida  regalis,  Eqiiisetum  fliiviatile, 
and  E.  hyemale.  In  Asia  and  our  region  are  found  Cryptogramma 
Stellari,  Asplenium  acrostichoides,  Onoclea  sensihilis,  Osmunda 
Claytoniana.  While  common  to  Eurasia  and  North  America  and 
found  in  our  region  are  such  forms  as  Phegopteris  polypodioides, 
P.  Dryopteris,  Onoclea  Strutliioptcris,  Osmunda  cinnamomea, 
Ophioglossum  vulgatiim,  Botrychinm  ternatum,  Equisetum  pratense, 
E.  syhaticum,  E.  variegatum,  Lycopodium  annotinum,  and 
L.  complanatum. 

It  must  be  evident,  then,  that  much  of  the  fauna  and  flora 
in  the  northern  part  of  the  world  before  the  glacial  advance 
began  was  common  to  Eurasia  and  North  America,  and  that 
this  life  common  to  the  two  continents  included  many  forms  now 
found  pretty  well  south.  Possibly,  too,  since  the  glacier 
retreated  there  has  been  land  continuity  between  Asia  and 
North  America,  and  an  invasion  route  has  led  from  Eastern 
North  America  through  the  Northwest  to  Asia  with  movements 
of  plants  and  animals  proceeding  in  both  directions.  Much 
additional  evidence  must  be  accumulated  before  this  last  point 
can  be  satisfactorily  settled. 


AN  OUTLINE  OF  SOME  OF  THE  IMPORTANT  PLANT 
AND  ANIMAL  ASSOCIATIONS 

Associations  Changing  Successively  as  Land  Construction  Goes  on 

The  Filling  Lake  in  the  Dune  Area 


I. 

2. 


4- 

5. 
6. 


7- 
8. 


The  beach  association 
Fore-dune  association 
Cottonwood  association 

Transition  zone 
Pine  association 
Black  oak  association 
Mixed  oak  association 

Oak-hickory  association 


Predatory  beetle  association 

Digger-wasp  association 
Large  tiger  beetle  association 
Cicindela  hirticollis  association 
Ant-lion  association 
Tree  frog  association 

Green  tiger  association 
Wood  frog  association 


Beech-maple  association 

(For  the  last  two  see  p.  306) 
The  filling  pond  or  small  lake  leads  on  to 
a)  the  wet  prairie  and  finally  to  the  dry  prairie 
h)  the  swamp  with  white  ash-elm  association,  and  finally  to  the  cli- 
max forest 
c)   the  sphagnum  bog  and  tamarack  swamp.     The  early  stages  of 
these  are  practically  identical,  namely  (7  is  usually  wanting  in  c) 
Bare  bottom  association  Lampsilis  luteolus  association 

Chara  association  Bloodworm  association 

Utricularia  Myriophyllum  association     Ischniira  vcrticalis  association 
They  then  differentiate  as  follows: 


{a) 


10.  Water  lily  association 

11.  Bulrush  association 

12.  Carex-Scirpus  diS?>OQ.\aX\on 

13.  Swamp  grass  association 


Painted  turtle  association 
Marsh  wren  association 
Green  flatworm  association 
Bobolink  association 


Andropogon  furcatus,  meadow  lark  association  (see  p.  306) 


(b) 

10.  Water  lily  association 

11.  Bulrush  association 

14.  Cat-tail  association 

15.  Buttonbush-prickly  ash  association 

305 


Painted  turtle  association 
Marsh  wren  association 
Redwing  association 
Succinea  association 


3o6       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


1 6.  Ash-elm  association  Green  heron  association 

In  steep-sided  ponds  this  last  may  be  replaced  by  the 

17.  Swamp  white  oak  association,  which  gives  place  to  the  oak  forest 


(c) 


18.  Floating  sedge  association 

19.  Sphagnum-Cassandra  association 

20.  Tamarack  association 


>    Northern  locust  association 


2 1 .  The  flood-plain  or  elm-soft  maple  association 

This  is  subdivided  into 

22.  The  bare  river  margin 

23.  Ragweed-sunflower  association 

24.  Willow  association 

25.  Young  ash-elm-maple  association 

26.  Mature  elm-maple  association 


Spotted  sandpiper  association 
Plant  bug  association 
Cecropia  association 
Yellow  warbler  association 
Tanager  association 


27. 

28. 
29. 


30- 
.SI- 

32. 


2>2>- 


34- 


The  flood-plain  association  is  stratified  like  the  climax  forest  (which 
see)  and  the  several  strata  may  be  named  as  in  the  climax  forest  though 
the  constituent  plants  and  animals  will  be  somewhat  dissimilar. 

Associations  that  Are  Relatively  Permanent,  the  Climax 
OF  Constructive  Processes,  Known  as  Climax 

Associations 
They  are: 

The  prairie  or  Andropogon  Jurcaius        Meadow  lark  association 

association 

The  oak-hickory  association  Green  tiger  association 

The  beech-maple  association  Wood  frog  association 

Each  of  these  is  subdivided.     In  addition  to  the  prairie  grasses 

other  plants  are  conspicuous,  and  several  types  of  prairie  may  be 

distinguished  in  addition  to  the  wet  prairie  (bobolink)  and  the  A  ndro- 

pogon  furcatus  (meadow  lark)  prairie. 

High  prairie  or  Silphium  association 

Very  dry  or  Eryngiiim  association 

Thin  soil,  rock  bottom,  prairie  clover 

association 

The  oak-hickory  and  beech-maple  forests  each  have  a 

Forest  margin  or  Crategus  association     Brown  thrasher  association 
Each  is  divisible  into  successive  strata,  much  alike  in  the  two  except 
for  variations  in  the  abundance  of  the  constituent  forms. 

The  forest  crown  association  Tree  cricket  association 


Jumping  spider  association 
Leaf  hopper  association 


OUTLINE  OF  PLANT  AND  ANIMAL  ASSOCIATIONS     307 

35.  The  tall  shrub  association  Epeira  association 

2,6.  The  low  shrub  association  Wood  nymph  association 

37.  The  ground  association  Snail  association 

This  in  turn  may  be  subdivided  into 

38.  Litter  association  Thousand  leg  association 

39.  Rotting  log  association  Horned  Passalus  association 

40.  Fungus  association  Fungus  beetle  association 

41.  Subterranean  association  Cicada  nymph  association 

Associations  Changing  Successively  as  Land  Destruction 

Occurs 

42.  The  shore  clay  bluff  association  Cicindela  Hmbalis  association 

43.  River  bluff  association  Kingfisher  association 

44.  Clay  ravine  association  Spearhead  dragon-fly  association 

45.  Rock  ravine  association  Phoebe  association 

46.  The  rock  hill  association 

The  River  Associations 
Communities  of  the  Intermittent  Streams 

47.  Intermittent  rapids  association  Black  fly  association 

48.  Intermittent  pool  association  Cambarus  association 

49.  Permanent  pool  association  Horned  dace  association 

Communities  of  Permanent  Streams 

50.  a)  The  spring-fed  brook  water  cress     Planar ian  association 

association 
b)  The  usual  alkaline  streams  associations  as  follows: 

5 1 .  The  very  rapid  water  (lotic)  society        Hydropsyche  association 

This  is  subdivided  into 

52.  The  brook  rapids  or  Rainbow  darter  association 

53.  The  creek  rapids  or  Fantail  darter  association 

54.  The  river  rapids  or  Banded  darter  association 

55.  The  moderately  rapid,  sandy  bottom  Campcloma  association 
association 

Which  may  be  divided  as  above 

56.  The  sluggish  water  (Limnetic)  sur-         Daphnia-Cypris  association 
face  society 

57.  The  sluggish  water  (Limnetic)  bot-         The  clam  association 
tom  society 

58.  The  estuary  association  subdivided  much  as  is  the  pond  society 

59.  (c)  The  acid  stream  association 


BOOK  LIST 

The  following  list  of  books  includes  some  of  the  most  useful 
in  determining  animals  and  plants  in  the  area  studied,  together 
with  a  few  titles  that  will  serve  to  introduce  the  reader  to  a 
more  extended  study  of  the  subject.  Additional  bibhographies 
will  be  found  in  these  latter. 

Salisbury  and  Alden,  Geography  of  Chicago  and  Its  Environs.  The  Geo- 
graphic Society  of  Chicago,  Bulletin  No.  i.  Chicago:  The  University 
of  Chicago  Press. 

Cowles,  H.  C,  The  Plant  Societies  of  Chicago  and  Vicinity.  The  Geographic 
Society  of  Chicago,  Bulletin  No.  2.  Chicago:  The  University  of 
Chicago  Press. 

,  ''The  Physiographic  Ecology  of  Chicago  and  Vicinity,"  Botanical 

Gazeite,  Vol.  XXXI,  pp.  73-108,  145-182. 

Goldthwaite,  J.  W.,  Physical  Features  of  the  Des  Plaines  River  Valley.  Illi- 
nois State  Geological  Survey,  Bulletin  No.  11.     Urbana,  111.,  1909. 

Sauer,  C.  O.,  Geography  of  the  Upper  Illinois  Valley.  Illinois  State  Geo- 
logical Survey,  Bulletin  No.  27.     Urbana,  111.,  1916. 

Gray^s  New  Manual  of  Botany.     New  York:  American  Book  Co.     7th  ed. 

Brown  and  Brittain,  Illustrated  Flora  of  the  Northern  States  and  Canada. 
New  York:   Charles  Scribner's  Sons.     3  vols. 

Hough,  Romyn  B.,  Trees  of  the  Northern  States  and  Canada.  Lowville, 
N.Y.:  published  by  the  author. 

Blakeslee  and  Jarvis,  Trees  in  Their  Winter  Condition.  New  York:  The 
Macmillan  Co. 

Parsons,  F.  T.,  How  to  Know  the  Ferns.    New  York:  Charles  Scribner's  Sons. 

\]ti(1qt\\oo(1,'L.'M.,  Our  Native  Ferns.     New  York:  Henry  Holt  &  Co. 

Grout,  A.  J.,  Mosses  with  a  Hand-Lens.  Published  by  the  author,  360 
Lenox  Road,  Brooklyn,  N.Y. 

Dunham,  E.  M.,  How  to  Know  the  Mosses.     Boston:  Houghton  ]\Iifflin  Co. 

Mcllvane,  Chas.,  One  Thousand  American  Fungi.  Indianapolis:  Bobbs- 
Merrill  Co. 

Shelford,  V.  E.,  Animal  Communities  hi  Temperate  America.  Chicago: 
University  of  Chicago  Press. 

Hancock,  J.  L.,  Nature  Sketches  in  Temperate  America.  Chicago:  A.  C, 
McClurg  &  Co. 

308 


BOOK  LIST  309 

Downing,  E.  R.,  Source  Book  of  Biological  Nature-Study.  Chicago:  Uni- 
versity of  Chicago  Press. 

Stone  and  Cram,  American  Animals.     New  York:   Doubleday  Page  &  Co. 

Cary,  Charles  B.,  The  Mammals  of  Illinois  and  Wisconsin.  The  Field 
Museum  of  Natural  History,  Publication  No.  153.     Chicago. 

Chapman,  F.  ]\I.,  Hand  Book  of  the  Birds  of  Eastern  North  America.  New 
York:  D.  Appleton  &  Co. 

Reed,  C.  K.,  Birds,  Land  and  Water.     New  York:  Doubleday  Page  &  Co. 

Ditmars,  R.  L.,  The  Reptile  Book.     New  York:   Doubleday  Page  &  Co. 

Dickinson,  ]\Iary  G.,  The  Frog  Book.     New  York:   Doubleday  Page  &  Co. 

Forbes  and  Richardson,  The  Fishes  of  Illinois.  Natural  History  Survey 
of  Illinois,  Vol.  III.     Urbana,  111. 

Adams,  C.  C,  An  Ecological  Study  of  Prairie  and  Forest  Invertebrates. 
Bulletin  of  Illinois  State  Laboratory  of  Natural  History,  Vol.  XI, 
September,  191 5. 

Comstock,  J.  H.,  Spider  Book.     New  York:   Doubleday  Page  &  Co. 

■,  Manual  for  the  Study  of  Insects.     Ithaca,  N.Y.:   The  Comstock 

Publishing  Co. 

Lutz,  Frank  E.,  Field  Book  of  Insects.     New  York:   G.  P.  Putnam's  Sons. 

Holland,  W.  J.,  The  Moth  Book.     New  York:  Doubleday  Page  &  Co. 

— ,  The  Butterfly  Book.    New  York:  Doubleday  Page  &  Co. 

Needham  and  Hunt,  Dragonflies  of  Illinois.  Bulletin,  Illinois  State  Labo- 
ratory of  Natural  History,  Vol.  VI,  September,  1901. 

Williams,  E.  B.,  Dragonflies  of  Indiana.  Twenty-fourth  Annual  Report  of 
the  Indiana  Department  of  Geology  and  Natural  History,  1895. 

Garman,  Philip,  The  Damsel-flies  of  Illinois.  Bulletin,  Illinois  State  Labo- 
ratory of  Natural  History,  Vol.  XII,  June,  191 7. 

Blatchley,  W.  S.,  Colcoptera  Known  to  Occur  in  Indiana,  Published  by  the 
author,  Indianapolis,  Ind. 

— — — ■,  Orthoptera  of  I  Indiana,  Tw^enty-sixth  Annual  Report  of  the  Indiana 
State  Department  of  Geology,  1901. 

Baker,  F.  C,  Mollusca  of  the  Chicago  Area,  Part  I,  "Clams,"  Part  II, 
"Slugs  and  Snails,"  Chicago  Academy  of  Science. 

Needham  and  Lloyd,  Life  of  Inland  Waters.  Ithaca,  N.Y.:  The  Comstock 
Publishing  Co. 

Ward  and  WTiipple,  Freshwater  Biology.     New  York:  John  Wiley  &  Sons. 


Fig.  452. — Map  of  Region  about  South  End  of  Lake  Michigan,  and  an  In 

The  Dune  areas  are  dotted  in.     This  territory  really  occupies  a  larger  area  about  Lake  Calumet  and  to 
the  purposes  of  this  book.     *This  sign  indicates  the  Tamarack  bog.     Electric  lines  are  thus  shown 

A  few  of  the  main  automobile  roads  out  of  Chicago  are  shown  by  a  single  line .     They  are 

map  correspond  to  the  numbers  on  the  inset  map,  which  indicates  how  the  city  streets  connect  up  with  the  ; 


r^ 


OLN 


=^ 


■'■'A* 

■  *H*  V-' 


^:.'-i->.yi- 


5fllNTJoS£l 


'  Showing  the  Main  Automobile  Routes  Out  of  the  City  of  Chicago 

south  and  east,  but  manufacturing  plants  and  railroads  have  so  altered  it  that  it  is  nearly  valueless  for 
ler  signs  are  conventional. 

drawn  to  show  the  route  in  detail,  but  merely  the  general  direction.     Numbers  in  triangles  on  the  large 
mobile  roads. 


INDEX 

Important. — The  page  references  to  plants  and  animals  are  given,  usually,  opposite  their 
scientific  names,  under  such  groups  as  mammals,  fish,  flowering  plants,  shrul^s,  etc.  To  aid  those 
not  familiar  with  the  scientific  names,  the  common  names  are  given,  .alphabetically  arranged,  with 
the  equivalent  scientific  names.  Thus  to  find  the  page  reference  to  "Bcdstraw"  look  for  the  common 
name  and  note  the  scientific  name.  Then  turn  to  "Flowering  plants,"  under  which  it  will  be  found 
with  page  references. 


Acadian  period,  46,  47 

Adaptations:    to  aquatic  life,   loi;    to 
light,  loi 

Adder's    tongue,    Erythroniimi    anieri- 
camim 

Aftonian  glacial  period,  57 

Alumroot,  Hcuchcra  amcricana 

Amphibians,     Frogs,     Salamanders, 
Toads : 

— Bufo  lentiginosus,  toad,  102,  152,  255 
— Chorophilns  nigritus,  spring  peeper,  94 
— Dicmictylus  viridcscens,  the  eft,  188, 

— Hyla: 

pickeringii,  165,  166,  219 
versicolor.  165,  166,  219 

— Plcthcdoti  cincrciis,  red-backed  sala- 
mander, 219 

— Rana: 

catesbeiana,  bullfrog,  240 
clamata,  green  frog,  240 
pdustris,  pickerel  frog,  240,  241 
sylvatica,  219,  220 
virescens,  leopard  frog,  240 

Amphibole,  72 

Amygdaloid,  73 

Anacharis,  see  Flowering  plants 

Anemone,  Anemonella  thallictroides 

Angelica,  see  Flowering  plants 

Animal  census,  150 

Ant,  carpenter,  165 

Anticline,  18 

Ant-lion:    association,    150,    159,    163; 
Myrmelion,  160 

Aphids,  165 

Aquatic  insects,  adaptations  of,  104 

Aquatic  leaf  form,  102,  103 

Arachnida,  Spiders,  Mites: 

— Argiopc,  the  orb  weaver,  188,  190 
— Dendryphantes  octavus,  158 
— Dolomedes  sexpunctatus,   diving  spi- 
der, 104 


— Epeira  gigas,  220,  223,  225 

— Ilydrachna,  red  water  mite,  94 

— Limnocharcs   aqiiaticus,   water   mite, 

— Lycosa  wrightii,  burrowing  spider,  99, 

— Neocosoma  arabesca,  220,  223,  225 

— Pardosa  lapidicina,  260,  261 

— Pliidippus  audax,  223,  225 

— Philodromus  alaskcnsis,  158 

— Tetragnalha     laboriosa,     long-bodied 

spider,  270,  271 
■ — Theridiufn  spirale,  159 
— Trochosa  cinerea,  sand-colored  spider, 

152,153 
— Xysticus  formosus,  158 

Arcella,  290 

Archaeozoic,  30,  31,  41 

Arrowhead,  Sagittaria  lalijolia 

Ash-elm  association,  241 

Aster  blossom,  spider  of,  108 

Aster,  rush.  Aster  junceiis 

Atmosphere,  beginnings,  26 

Back  swimmer,  see  Hcmiptcra 
Baneberry,  Actaea 
Bare-bottomed  ponds,  1 79 
Basalt,  19,  75,  76 
Bat,  brown,  see  ISIammals 
Beach  association,  115,  119 
Bearberry,  Arctostapkylos  Uva-ursi 
Bee,  carpenter,  219 
Beetles,  sec  Coleoptera 
Beggar-ticks,  Bidens  frondosa 
Bedstraw,  Galium  apariuc 

Bellflower,    marsh.    Campanula    apari- 

noidcs 
Bellwort,  Uvularia  grandijlora 
Bender,  see  Crustaccac 
Bergamot,  Monarda  jislulosa 
Betelgeuse,  21 


311 


312       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Birds,  bones  of,  105 
Birds: 

— Bittern:  American,  240,243;  least, 240 
— ^^Blackbird:  red-winged,  240;  yellow- 
headed,  240 
— Bluebird,  166 
— Blue  jay,  166 
— Bobwhite,  229,  269 
— Brown  thrasher,  229 
— Bunting: 

indigo,  229,  270 
lark,  254 
— Cardinal  grosbeak,  270 
— Catbird,  229 
— Chewink,  229,  269 
— Chickadee,  159,  270 
— Crow,  166 

— Cuckoo,  black-billed,  270 
— Curlew,  Hudsonian,  757 
— Dickcissel,  254 
— Flycatcher : 

great  crested,  220,  270 
least,  166 
— Gallinule,  241 
— Godwit,  Hudsonian,  757 
— Goldfinch,  229 
— Grosbeak,  cardinal,  270 
— Hawk : 

red-shouldered,  166,  202 
red- tailed,  166 
— Heron,  green,  242 
— Kingbird,  156 
— Kinglet : 

golden-crowned,  159 
ruby-crowned,  159 
— Knot,  751 
— Lark : 

meadow,  254 
prairie  horned,  254 
— Mourning  dove,  229 
— Oriole,  Baltimore,  270 
— Ovenbird,  220,  270 
—Owl: 

great  horned,  220 
screech,  220 
— Phoebe,  269 

— Pewee,  wood,  166,  220,  269 
— Plover: 

killdee,  752 
piping,  752 
semipalmated,  752 
— Prairie  chicken,  254 
— Rails,  241 
— SanderHng,  757 
— Sandpiper: 
least,  151 


semipalmated,  757 
solitary,  271 
spotted,  752,  270,  271 
— Shrike,  229 
— Sparrow : 

chipping,  229 
grasshopper,  254 
song,  229 
vesper,  254 
— Swallow : 

bank,  156,  265 
rough-winged,  265 
tree,  ij6 
— Tanager,  scarlet,  220 
— Thrush : 

hermit,  270 
Wilson's,  270 
wood,  166,  220,  270 
— Turnstone,  757 
— Vireo,  red-eyed,  220 
— Warbler : 

black  and  white  creeping,  166,  220 
black-throated  green,  159 
pine,  159 
yellow,  166,  220 
— Whippoorwill,  269 
— Willet,  757 
— Woodpecker: 
downy,  159 
hairy,  159 
red-headed,  166 
— Wren : 

marsh,  240 
nest,  242 

Black  oak  association,  115,  132 

Bladderwort,  Utricularia  vulgaris 

Bladderwort-milf oil  ponds,  179 

Blazing  star,  Liatris 

Bloodroot,  Sangidnaria  canadensis 

Bloodworm  ponds,  179 

Blow-out,  14,  141 

Bluebell,  Campanula  rotutuiifolia 

Blue  Island,  36,  78,  83,  85,  86 

Bluffs,  lake  shore,  2,  259,  260 

Boneset,  Rupatoriimi  perjoliatum 

Braiderwood,  13 

Breccia,  70 

Bronze  tiger  association,  150,  157,  163 

Brown-eyed  Susan,  Riidbeckia  hirla 

Bugs,  see  Hemiptera 

Bugseed,  Corispermum  hyssopijolium 

Bulrush,  Scirpus 


INDEX 


2>^2> 


Bulrush  zone,  237 
Bur  reed,  Sparganum  eurycarpum 
Butter  and  eggs,  Linaria  vulgaris 
Butter-cup,  water,  Ranunculus  aquatilis 
Butterflies,  see  Lepidoptera 
Butterfly  weed,  Asclepias  tuber os a 

Caboma,  103 

Cactus,  Opuntia  Rafinesquii 

Caddis     fly:      Leptoccra,     175;      net- 
building,  see  Hydro  psyche 

Caddis  worm.  Goer  a,  169 

Calcite,  71 

Calumet  stage  of  Lake  Chicago,  82,  83 

Canadian  period,  46,  47 

Canon  Diablo,  23,  24 

Cardinal  flower.  Lobelia  cardinalis 

Carrot,  wild,  Daucus  carota 

Cassandra  zone,  198 

Cat-tail,  Typha 

Cat-tail  zone,  238 

Caves,  10 

Cenozoic,  30,  31 

Chalcopyrite,  72 

Champlain  Sea,  88  • 

Chalk,  yi 

Chara  ponds,  179 

.Checkerberry,  GauUheria  procumbens 

Cherry,  ground,  Physalis 

'  Cheveril,  Anthricus  cerefolium 

Chicago:     Lake,    see    Lake    Chicago; 
site  of,  50,  52,  57,  64,  88 

Chickweed,  Stellaria  aquatica 

Chirotenetes  siccus  May-fly,  289 

Chlorite,  71 

Cicada,  see  Heniiptera 

Cicely,  sweet,  Osmorhiza  Claytoni 

Cinquefoil:  beach,  Poteniilla  canadensis; 

shrubby,    P.    fruticosa;     silver,    P. 

Anserina 
Clams,  distribution  of,  279 
Clams  (Pelecypoda) : 

— Alasmodonta  marginata,  169,  170,  171 
— Anadonta  grandis,  169,  170,  171 
— Lampsilis  luteola,  169,  170,  171,  234 
— Sphacrium  simile,  184,  184 

Clay  pinnacles,  10 


Clearweed,  Pilea  pumila 

Cleavage,  69,  170 

Climax  forest,  202 

Closed  gentian,  Gentiana  Andreu'sii 

Clover: 

— Bush,  Lespedeza  capitata 

— Prairie,  Petaloslemwn  purpiireum 

— White  sweet,  Melilotus  alba 

Coal  beds,  51 

Cocklebur,  Xanthium  echinalum 

Coleoptera,  Beetles: 

— Alaus  oculatus,  eyed  elater,  219 

— Balaninus,  nut  weevil,  223 

— Boletothcrus  bifurcus,  fungus  beetle, 
219,  220 

— Buprestidac,     metallic     wood-boring 
beetles,  158,  219 

— Calloides  nobilis,  225,  226 

— Calosonia: 

calidum,  the  fiery  hunter,  153,  75J 
scrutator,  the  searcher,  153,  755 

— Chalco phora    liberta,   metallic   wood- 
borer,  158,  159 

— Chalepus: 

nervosa,  223 
rubra,  223 

— Chrysobothris  femorata,  flathead  apple- 
tree  borer,  226 

— Cicindela: 

ancocisconenses,     sphagnum     tiger 

beetle,  149,  201 
cuprascens,  copper  tiger  beetle,  148, 

149,  153  .       ^ 

formosa  generosa,  large  tiger  beetle, 

148,  i49>  158 
hirticollis,  148,  149 
lepida,  white  tiger  beetle,  148,  149, 

153 
limbalis,  clay  blufl'  tiger,  149,  260 

re  panda,  149,  149 

scutellaris    lecontci,    bronze     tiger 
beetle,  148,  149,  158 

scxguttata,  green  tiger  beetle,  149, 
149 

tranquebarica,  149 
— Cicindelidac,  tiger  beetles,  148,  i4g 
— Diapcris  maculata,  fungus  beetle,  219, 

220 
— Disonycha  quinqucviltata,  154,  133 
— Dytiscus,  di\'ing  beetle,    104,   larva, 

'186,  188,  239 
— Elaphidion  villosum,  223 
— Elateridae,  click  beetles,  219 
— Eupsalis  minuta,  oak  borer,  227,  228 


314        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Colcoptcra,  Bee  ties — Cc  nt  inued 

— Galerites  janus,  yellow-legs,  ijj 

— Galetucella  luteola,  223 

— Graphisuriis  fasciatus,  225,  226 

— G>'n'w//5,  whirligig  beetles,  105, 186,187 

— Hydrophilidae,     water- scavenger 

beetles,  186,  239 
— Lacon  rectangidaris,  161 
— Liophus  alpha,  226 
— Meracintha  contrada,  darkling  beetle, 

228 
— Molorchns  bimaculatus,  225,  226 
— Monohammus  scutdlatus,  a  long-horn 

beetle,  158,  159 
— Nyctohates  pennsylvanica,  228 
— Oncideres  cingulatus,  hickory  girdler, 

222 
— Parandra  hriinea,   heartwood   borer, 

227,  227 
— Passalus  cornutns,  horned  Passalus, 

219,  220,  227,  228 
— Pisenus    humeralis,    fungus    beetle, 

219,  220 
— Pledrodera  scalator,  cottonwood  borer, 

156 
— Prasocuris  phellandrus,  161 
— Pscphenus  lecontei,  brook  beetle,  287, 

289 
— Saperda: 

lateralis,  226 

tridentata,  elm  borer,  224,  225 

vestile,  226 
— Sphenophorus,  snout  beetles,  155 
— Stenosphenius  tenehri aides,  228 
— Tetraopes  tetraophthalmus,  milkweed 

beetle,  230 
— Tymnes: 

matasternalis,  leaf  beetle,  223 

tricolor,  leaf  beetle,  223 
— Uloma  impressa,  darkling  beetle,  228 
— Xanthoma  lo-notata,  223 
— Xylopinus  saperdioides,  227 
— Xylotrechus  colonus,  rustic  borer,  224, 

225 

Columbine,  Aquilegia  canadensis 

Compass  plant,  Silphium  laciniatum 

Conefiower,  Brauneria  purpurea 

Conglomerate,  71 

Continents,  41 

Corals,  49,  50 

Corn  plant  association,  108 

Corn  root  aphis,  108 

Cotton-boll  weevil,  301 

Cottonwood  association,  115,  120,  122 


Cress,  bitter,  Cardamine 

Crickets,  see  Orthoptera 

Crustaceans: 

— Aero  perils,  290 

— Asellus,  the  water  sow  bug,  93,  94 

— Cambarus: 

dio genes,  252 

gracilis,  252,  254 

virilis,  crayfish,  234 
— Canthocampus,  93,  290 
— Cyclisticus  convcxus,  sow  bug,  218 
—Cyclops,  93,  94,  290 
— Cypris  marginata,  93,  g4 
— Daphnia,  93,  94,  290 
— Eubranchi  pus     serratus,     the     fairy 

shrimp,  gz,  93 
— Eucrangonyx  gracilis,  bender  or  scud, 

178 
— Gammarus  fascial  us,  the  bender,  93, 

177 
— Hyaldla  knickerbockcri,  bender,  177 
— Leplohora,  290 
— Palaemonctcs  paludosus,  the  shrimp, 

93,  240 
— Porchdlio  rathke,  sow  bug,  218 

Crystal,  68 

Culver's  root,  Veronica  virginica 

Cup  plant,  Silphium  perfoliatum 

Dalles  of  the  Wisconsin,  6,  7 

Damsel  fly,  see  Odonata 

Damsel-fly  nymph,  105,  186 

Del  wood  Park,  10 

Deposition,  15;  of  river,  16 

Desplaines  River,  3,  66,  80,  83 

Desplaines  Bay,  80,  83 

Devonian  period,  S3,  38,  5°,  55,  58 

Diabase,  75 

Difflugia,  290 

Digger  wasp  association,  150,  154,  156, 
163 

Diorite,  7s,  76 

Diptera,  Flies: 

— Chironomus,  a  midge,  175,  287 

— Corethra,  290 

— Culex,  mosquito,  104,  187 

— Exoprospa,  bee  fly,  154 

— Simidium,  black  fly,  186,  287 

Distribution    of    plants    and    animals, 
factors  determining,  90 

Dobson,  larva  of  Corydalis  cornuta,  186 


INDEX 


315 


Dolomite,  72 

Dragon  flies,  distribution  of,  in  streams, 

280 
Dragon  fly,  see  Odonata 
Dragon,  green,  Arisaema  dracontium 

Dunes,  13,  112,  123,  150;  formation  of, 
13,  112,  114,  116,  122;  plants  of, 
tabulation,  144-47;   rate  of  advance 

of,  13 
DuPage  River,  67 

Dutchman's  breeches,  Dicentra  cucid- 

laria 
Dyke,  39,  40 

Earth:  crust  of,  17,  29;  heat  of,  25; 
origin  of,  22,  25 

Earth  worm,  165 

Erosion:   agents  of,  2,  27;   amount  of, 

41 
Eskers,  68 

Feldspar,  72 
Ferns : 

— Adiantiim  pedatiim,  maidenhair  fern, 

210,  213 
— Aspidium: 

cristatum,  199,  200,  247 

marginale,  margined  fern,  210,  213 

novaboracense,  pale  wood  fern,  210, 

213 

spinulosum,  florist's  fern,  210,  213 
Thelypteris,  marsh  fern,  195,  198 
— Asplenlmn: 

acrostichoides,     wood     spleen  wort, 

210,  213 
angusti folium ,  spleenwort,  100 
Filix-femina,  lady  fern,  210,  213 
— Coniptosorus     rhizophyllus,     walking 

fern,  266,  269 
— Cystopteris: 

bulbifera,  bladder  fern,  264,  265 
fragilis,  fragile  fern,  100,  264 
— Onoclea: 

sensihilis,  sensitive  fern,  179,  180, 

221 
strut hiopteris,  ostrich  fern,  210,  213 
— Osmunda: 

Claytoniana,    Clayton's    fern,    in- 
terrupted fern,  180, 181,  182,  221, 
270 
cinnamomea,  cinnamon  fern,    180, 

182,  182,  200,  221,  270 
regalis,  royal  fern,   180,  181,   182, 
200 


— Pellaea  atro purpurea,  purple-stemmed 

clifif  brake,  265 
— Phegopteris  polypodioides,  beech  fern, 

210,  213 
— Polopodium  vidgare,  rock  polypody, 

268,  269 
— Polystichknn  acrostichoides,  Christmas 

fern,  210,  213 
— Pteris   aquilina,   bracken   fern,    211, 

214,  221 

Fish: 

— Bass: 

black,  large-mouthed,  Micropterus 

salmoides 
black,  small-mouthed,  M.  dolomieu 
rock,  AmhlopUtes  rupestris 

— Bluegill,  Lepomis  pallidus 

— Bullhead: 

black,  Ameiurus  melas 
spotted,  A.  nehulosus 

—Cat: 

mud,  Leptops  olivaris 
stone,  Notorus  flavus 
tadpole,  Schilheodes  gyrinus 

— Chub,  river,  Hybopsis  kentuckiensis 

— Crappie,  black,  Pomoxis  sparoides 

— Dace: 

black-nosed,  Rhinichthys  atronasiis 
horned,  Semotilus  atromacidatus 
red-bellied,     Chrosomiis    erythro- 
gaster 

— Darter: 

banded,  Etheostoma  zonale 
black-sided,  Hadropteriis  aspro 
fantail,  Etheostoma  jiabellare 
Johnny,  Boleosoma  nigrum 
rainbow,  Etheostoma  coendeum 
sharp-headed,   Iladroptcrus  phoxo- 
ccphalus 

— Dogfish,  Amia  calva 

— Miller's  thumb,  Cottus  ictalops 

— Minnow: 

blunt-nosed,  Pimephales  notatus 

Cayuga,  Notropis  cayuga 

mud,  Umbri  liml 

red-faced,  Notropis  riibrifrons 

red  fin,  N .  lutrensis 

straw-colored,  N.  blennius 

sucker-mouthed,  Phenacobius  mira- 

bilis 
top,  Fiindidus  dispar 

— Perch,  }'cllow,  Perca  Jiavescens 

—Pike: 

Esox  liicins 

grass  or  small  pickerel,  E.  vermicu- 
latus 


3i6        A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Fish — Continued 

— Pumpkin  seed,  Eupomotls  gibbosus 

— Redhorse,  Moxostoma  aureohnn 

— Sculpin,  Cottiis  ictalops 

— Shad,  gizzard,  Dorosoma  cepedianum 

— Shiner : 

Notropis  atherinoides 

common,  N .  cornutus 

golden,  Abramis  crysolencas 
— Silversides,   brook,    Lapidesthes   sic- 

ciilus 
— Stone  roller,  Campostoma  anomahim 
— Sucker: 

chub,  Erimyzon  sucetta 

common,  Catostonms  commersonii 

hog,  C.  7iigricans 
Fish: 
— Abramis   crysolencas,   golden   shiner, 

774,  175,  284 
— Ambloplites  rupestris,  rock  bass,  284, 

285 
— Ameiurus: 

melas,  black  bullhead,  184,  284 

nebidosns,  spotted  bullhead,  774, 176 
— Amia  calva,  dogfish,  284 
— Boleosoma    nigrum,    Johnny    darter, 

234,  282,  283 
— Campostoma  anomalum,  stone  roller, 

283,  284 
— Catostonms: 

commersonii,  common  sucker,  283, 
284 

nigricans,  hog  sucker,  284 
— Chrosomus    erythrogastcr,    red-bellied 

dace,  282,  283 
— Cottiis  ictalops,  blob,  sculpin,  234 
— Doroso?na  cepedianum,  gizzard  shad, 

284 
— Erimyzon  sucetta,  chub  sucker,  77^, 

17s,  284 
— Esox: 

lucius,  pike,  168,  777,  172 

vermiculatus,  grass  pike,  284 
— Etheostoma: 

coeruleum,    rainbow    darter,    282, 
283,  28S 

flabellare,  fan-tailed  darter,  285,  286 

zonale,  banded  darter,  284,  285 
— Eupomotis   gibbosus,   pumpkin   seed, 

173,  234,  284 
— Fundulus  dispar,  striped  top  minnow, 

239,  284 
— Hadropterus: 

as  pro,  black-sided  darter,  285,  286 

phoxocephaltis,  sharp-headed  darter, 
286,  287 


— Hybopsis  kentuckiensis,  river  chub,  284 

— Lapidesthes  sicculus,  brook  silver- 
sides,  284 

— Lepomis  pallidus,  bluegill,  173,  234, 
284 

— Leptops  olivaris,  mud  cat,  284 

— Micropterus: 

dolomieu,      small-mouthed      black 

bass,  234,  284 
salmoides,     large-mouthed     black 
bass,  234,  284 

— Moxostoma  aureolum,  red  horse,  168, 
284 

— Notropis: 

atherinoides,  shiner,  772,  172 
blennius,    straw-colored    minnow, 

234,  284,  285 
Cayuga,  Cayuga  minnow,  168,  171, 

iy2 
cornutus,  common  shiner,  169,  171, 

.284 
lutrensis,  redfin,  284 
rubrifrons,  red-faced  mmnow,  284 

— Notorus  flavus,  stone  cat,  284 

— Perca  flavescens,  yellow  perch,  234, 
284 

— Phenacobius  mirabilis,  sucker- 
mouthed  minnow,  285,  286 

— Pimephales  notatus,  blunt-nosed  min- 
now, 234,  282,  283 

— Pomoxis  sparoides,  black  crappie,  234, 
284,  285 

— Rhinichthys  atronasus,  black-nosed 
dace,  283 

— Schilbeodes  gyrinos,  tadpole  cat,  174, 
I75,\'j(i,  284 

— Semotilus  atromacidatus,  horned  dace, 
281,  283 

— Umbri  limi,  mud  minnow,  77^-,  174, 
185,  284 

Fish,  distribution  of,  in  streams,  283 

Fishes: 

—Age  of,  50 

— Fossil,  50 

Flag,  sweet.  Acorns  Calamus 

Flathead,  67 

Flies,  see  Diptera 

Floating  sedge  zone,  196 

Flood  plain,  17,  272 

Flowering  plants  (see  also  Vines,  Shrubs, 
and  Trees;  for  common  names  see 
General  Index) : 

— A  cerates  viridiflora,  green  milkweed, 
117,  119,  132 


INDEX 


317 


Flowering  Plants — Continued 

— Acorns  Calamus,  sweet  flag,  238,  239 

— Actaca: 

alba,  white  baneberry,  210,  210,  211 

rubra,  red  baneberry.  210 
— Agrostis  pcrennans,  thin  grass,  244, 

246 
— Allium  cermmm,  wild  onion,  248,  250 
— Ammophila  arcnaria,  marram  grass, 

iig,  120 
— Amorpha  canescens,  lead  plant,  250, 

254 

— Anacharis,  103 

— A^tdropogon  fur  cat  us,    prairie    grass, 

24s,  247,  249 
— Anemone   cylindrica,    thimble    weed, 

132,  133,  134. 

— Anemonclla  thalictroides,  anemone,  92 
— Angelica  atro purpurea,  angelica.  ?-66, 

268 
— Aquilegia  canadensis,  columbine,  132, 

133,  209,  264,  269 

— Arabis  lyrata,  rock  cress,  132, 134, 135 
— Aralia  nndicauUs,   sarsaparilla,   264, 

267,  269 
— Arethusa  hulhosa,  194,  197,  198 
— Arisaema: 

dracontium,  green  dragon,  2og,  210 

triphyllum,  Jack-in-the-pulpit,  208, 
2og 
— Artemisia  caudala,   wormwood,  117, 

118 
— Asarum  canadense,  wild  ginger,  209, 

275 
— Asclepias: 

cornuta,  common  milkweed,  106 
incarnata,  swamp  milkweed,  197 
syriaca,  common  milkweed,  229 
tuberosa,  butterfly  weed,  132,  135, 

137,  249 
— Aster  junceus,  199,  200 

— Bidens: 

frondosa,  beggar-ticks,  249 

purpurea,  237 
— Brasenla  Schreberi,  water  shield,  196 
— Brauneria  purpurea,  cornflower,  249, 

251 

— Cabonia,  water  moss,  103 

— Cakile  edentida,  sea  rocket,  115,  117, 

118 
— Calamagrostis   canadensis,   l)luc-joint 

grass,  244,  246 
— Calamovilfa  longijolia,  sand  reed  grass, 

iig,  120 
— Calapogon  pulchellus,  grass  pink,  194, 

197 
— Caltha  paluslris,  marsh  marigold,  179, 

274 


— Cammasia   esculenta,   wild    hyacinth, 

248,  249 
— Campanula: 

aparinoides,  marsh  bellflower,  io7 

rotund  ifolia,h\\XQhQ\\,  124,  126,  128, 
264,  269 
— Carex: 

aquatilis,  246 

conjuncta,  244,  246 

cristata,  244,  246 

filiform  is,  193,  196 

lupidiformis,  244,  246 

riparia,  193,  197,  246 

stricta,  244,  246 
— Cardamitte: 

bulbosa,  bitter  cress,  247,  248 

Douglassii,  247 

pennsylvanica,  247 
— Castalia  tuberosa,   white   water  lily, 

179,  196 
— Castilleja  cocdnea,  painted  cup,  18 j 
— Cerastium  vulgatum,  chickweed,  247, 

248 
— Ceratophyllum   demersum,   horn  wort, 

103,  178,  236 
— ChacropliyUum  procumbens,  cheveril, 

273,  274 
— Cirsium: 

arvense,  Canada  thistle,  228,  260 

lanceolatum,  spear  or  bull  thistle, 
228 

Pitchcrii,  sand  thistle,  118,  iig 

pumilum,  pasture  or  prairie  thistle, 

249      ..    . 
— Claytonia  virginica,  spring  beauty,  91, 

92,  209 

— Comandra   umbcllata,   bastard    toad- 
flax, 132,  133, /J4,  264 
-Coreopsis  grandiflora,  tickseed,    195, 
197 

— Corispermum  hyssopifolium,  bugseed, 
117,  118 

— Crotalia  sagit talis,  rattlebox,  266,  269 

— Cryptotaenia    canadensis,    honcwort, 

273,  275 
— Cydoloma  atriplicifolium,  winged  pig- 
weed, 117,  iig 
— Cypripedium       parvijlorum,      >-ello\v 

lady's-slipper,  138,  141 
— Daucus   carota.   Queen   Anne's   lace, 

wild  carrot,  266,  268 
— Dcntaria  laciniata,  toothwort,  91,  92, 

209 
— Dicenlra      cucullaria,       Dutchman's 

breeches,  91,  02,  209 
— Dodccatiicon   mcadia,    shooting    star, 

247,  249 
— Draba    caroliniana,    whitlow     grass, 


3i8       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Flowering  Plants — Continued 

— Drosera  rotimdifolia ,  sundew,  195,  197 

— Eleocharis  acicnlaris,  spike  rush,  235, 

238 
— Elodea,  water  weed,  236 
— Elynnis  canadensis,  r>'e  grass,  117,  iig 
— Eriophorum   gracile,    cottony    grass, 

195,  197.-  198 

— Eryngiiim  yuccifoliiim,  24Q,  253 

— Erythronium      amcricannm,      yellow 

adder's  tongue,  91,  92,  209 
— Eupatoriiim  perfoliatnm,  boneset,  266, 

268 
— Euphorbia: 

corollaia,  flowering  spurge,  132,  135, 

polygonifolia,  seaside  spurge,   117, 
119,  120 
— Galium  aparine,  bedstraw,  210,  210, 

212 
— Gatitheria  procmnbens,  checkerberry, 

124,  126 
— Gentiana  Andrewsii,  closed  gentian, 

107 
— Geranium: 

carolinianum,  wild  geranium,  132, 

135,  136 

■macidatHm.    wild    geranium,    136, 
138,  140,  141 
— Glyceria  nervata,  244,  246 
— Habenaria  lacera,  the  ragged  orchis, 

196,  198 

— Hepatica  triloba,  hepatica,   92,    138, 

140,  142,  209,  267 
— Heucheraamerica7ia, a.\uTnYoot,266y26g 
— Hieracleum    lanakim,    cow    parsnip, 

273,  275 
— Hydrophyllum     virginianum,     water 

leaf,  ^10,  210,  211 
— Hypericum  Kahnianum,   St.  John's- 

wort,  124,  126,  i2g 
— Impaticns: 

biflora,  touch-me-not,  100,  210,  212 

pallida,  212 
— Iris  versicolor,  blue  flag,  loi,  182 
— Juncus:  bog  rush 

balticus,  235,  238 

canadensis,  235,  237 

effusus,  235 

tenuis^  23s 
— Lactuca  scariola,    wild   lettuce,    loi, 

249 
— Lathyrus  maritimus,  beach  pea,  117, 

118 
— Lemna  minor,  duckweed,  234 
— Lespedeza  capitata,  bush  clover,  132, 

13  S  138 


-Liatris: 

cylindrica,  blazing  star,  137 
scariosa,  blazing  star,  13^ 
spicata,  blazing  star,  137,  245 

-Linaria    vulgaris,    butter    and    eggs, 
toad  flax,  107 

-Lithospermum-     canescens,     puccoon, 
124,  126,  i2g 

-Lobelia  cardinalis,  cardinal  flower,  248 

-Lnpinus  perennis,  lupine,   132,   134, 

134 
-Maianthemum   canadense,  false   lily- 

of-the-valley,  124,  127,  128,  264 
-Melilotns  alba,   white    sweet  clover, 

260 
-Monarda: 

fistidosa,  wild  bergamot,  132,  136, 

137 
punctata,  horse  mint,  124,  126,  i2g 

-Myriophyllum     hctcrophyllum,      mil- 
foil, 102,  103,  168,  178,  197,  236 

-Nymphaea  advena,  yellow  water  lily, 
179,  196. 

-Opuntia  Rafinesqiiii,  cactus,  98,  99, 
132 

-Osmorhiza    Claytoni,     sweet     ciceh^ 
210,  210,  212 

-Panax  trifoliiim,  ginseng,   210,   211, 
212 

-Panicum  virgatum,  switch  grass,  244, 
246 

-Parnassia  caroliniana,  grass  of  Par- 
nassus, 183 

-Pastinaca  sativa,  wild  parsnip,   266, 
268 

-Pedicularis     canadensis,     lousewort, 
wood  betony,  132,  135,  137,  267 

-Petalostemum      purpureum,      prairie 
clover,  250,  254 

-Phlox: 

divaricata,  wood  phlox,  209,  274 
pilosa,  hairy  phlox,  124,  i2g,  249, 
252 

-Phragmites  communis,  reed,  238,  239 

-Physalis,  ground  cherry,  229 

-Pilea   pumila,   clearweed,    100,    210, 
210,  212 

-Poa  triflora,  prairie  grass,  247 

-Podophyllum    peltatum.  May   apple, 
138,  140,  142,  228 

-Polygonatum  bijlorum,  Solomon's  seal, 
124,  210 

-Polygonum: 

lapathifolium,  smart  weed,  246,  248 
persicaria,  248 

-Potamogeton,   pond  weed,    178,   235, 
236 


INDEX 


319 


Flowering  Plants — Continued 

— Potent  ilia: 

Anscrina,  cinquefoil,  117,  118 
canadensis,  beach  cinquefoil,  118 
fruticosa,shYnhhycmqueio\\,i8j,iS4 

— Prcnanthes    alba,    rattlesnake    root, 
138,  140,  142,  264,  269 

— Proserpinaca      palustris,      mermaid 
weed,  247,  248 

— Ranuncidus  aqtiat His, water  buttercup, 
102,  236 

— Rudheckia  hirta,  brown-eyed  Susan, 
248,  251 

— Sagittaria  latifolia,  arrowhead,  2  3  7, 238 

— Sanguinaria  canadensis,  q2,  209 

— Sarracenia  purpurea,   pitcher  plant, 
iq8,  199 

— Saxifraga  pennsyhanica,  swamp  saxi- 
frage, 178,  180 

— Scirpus:  bulrush  or  club  rush 
atrovircns,  235,  237 
Torreyi,  235,  237 
validus,  23  s,  2J7 

— Scutellaria  galericulata,  skull  cap,  247, 
248 

— Silphium: 

laciniatum,  compass  plant,  loi 
perfollatum,  cup  plant,  107,  108 
terebinthinaceum,Yo^in\veed,  249, 252 

— Sisyrinchiuni  angustifolium,  blue-eyed 
grass,  124,  128,  182 

— Smilacina  racemosa,  false  Solomon's 
.  seal,  124,  128,  i2g 

— Sparganium    eurycarpum,    bur   reed, 
237,  238 

— Spartina  Michauxiana,  slough  grass, 
244,  246 

— Spiranthes    Romanzoffiana,    fragrant 
ladies'-tresses,  197,  198 

— Sporobolus  cryptandrus,  249,  252 

— Steironema  ciliatnm,   fringed    loose- 
strife, 273,  275 

— SymphocarpHS  foetidus,   skunk   cab- 
bage, 273,  274 

— Tcphrosia  virginiana,  hoary  pea,  132, 

134,  135 
— Thaliclniim  dasycarpum,  meadow  rue, 

266,  267 

— Tradescantia    virginica,     spiderwort, 

132,  133,  134,  269 
— Trientalis  americana,  star  flower,  1 24, 

127,  128 
— Trillium: 

grandiflorum ,  triUium,  92,  209  _ 

recurvatiim,  red  or  purple  trillium, 
92,  209 


— Typha: 

angustifolia,  narrow-leaved  cat- tail, 

lOI 

latifolia,  cat-tail,  lor,  238 
— Utricularia     vulgaris,      bladdcrwort, 

102,  103,  178,  236 
— Uvularia  gratidijlora,   bellwort,    124, 

126,  I  JO 
— Vallisneria,  tape  grass,  236 
— Verbascum  Thapsus,  mullein,  119, 120 
— Veronica  virginica.  Culver's  root,  248, 

250 
— Viola: 

blanda,  white  violet,  179,  248 

canadensis,    Canada    violet,     138, 
140,  142,  209 

palmata,  wood  ^'iolet,  209 

pedata,  bird's- foot  violet,  132,  135 

pedatafida,  248 

rostrafa,   long-spurred  violet,    138, 
140,  142,  209 

sagittata,  arrow-leaved  violet,  132, 
135,  182 
— Xant Ilium  echinatum,  cocklebur,  118 
— Xyris  caroloniana,  3'cllow-e}'ed  grass, 

182 
— Zizania  aquatica,  \\'ild  rice,  237,  238 
— Zizia  aurea,  golden  old  man,  248,  250 

Fold  of  rock  in  Illinois,  52,  54 

Food  supply  and  distribution,  106 

Fore-dune  association,  115,  119 

Forest  margin  association,  228,  261 

Forest  succession,  202 

Fossils,  28,  49,  5  ^  53 

Frost,  27 

Fracture,  yo 

Fraction  Run,  3,  8 

Frog,  hibernation  of,  105 

Frogs,  s.ce  Amphibians 

Frogs'  eggs,  94 

Gabbro,  7S,  76 

Galena-Platteville  limestone,  34,  38,  46, 

52,  54 
Galenite,  68,  7/ 

Galls  of  oak,  1O3,  164 

Gentian,  Gentiana  Andrcicsii 

Geologic  ages,  30 

Geranium,    wild,    Geranium    carol  in  ia- 
num;  G.  maculotum 

Ginger,  wild,  Asarum  canadensc 

Ginseng,  Panax  Irifolium 


320       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Glacial  drift,  63,  64,  68;  thickness  of,  63 

Glacial  bowlder,  60 

Glacial  periods,  57 

Glacial  period,  origin  of,  56 

Glacial  striae,  60,  61 

Glacier,  9,  19,  20,  56;  thickness  of,  62 

Glencoe,  4,11 

Glenwood  stage  of  Lake  Chicago,  79,  81 

Golden  old  man,  Zizia  aurea 

Gopher,  see  IMammals 

Granite,  yj,  76 

Grape,  wild,  see  Vines 

Grass: 

— Blue-eyed,  Sisyrinchium  angustifolium 

— Blue  joint,  Calamagrostis  canadensis 

— Cottony,  Eriophorum  gracilc 

— Dropseed,  Sporoholus  cryptandrus 

— Fowl  meadow,  Glycera  mrvata 

■ — Goose,  Potentilla  Anserina 

— Marram,  Ammophila  arcnaria 

— Of  Parnassus,  Parnassia  carol iniana 

— Prairie : 

A  ndropogon  furcatiis 

Poa  triflora 
— Rye,  Elymos  canadensis 
— Sand  reed,  Calamovilfa  longifolia 
— Thin,  Agrostis  perennans 
— Switch,  Panicum  virgatum 
— Whitlow,  Draha  caroliniana 
— Yellow-eyed,  Xyris  caroliniana 

Grasshopper,  see  Orthoptera 

Green  dragon,  Arisaema  dracontiiim 

Gypsum,  yi 

Hardness  of  minerals,  70 

Hematite,  72 

Helico psyche,  caddis  fly,  287,  188 

Hemiptera,  Bugs: 

— Arctocorixa   interrupta,    water    boat- 
man, 187,  188,  239 
— Belostoma,  lesser  waterbug,  186,  188 
■ — Bcnacus  griseus,  giant  waterbug,  104, 

186,  188,  239 

— Cicada linei,  cicada.  212,  221,  222,  224 
— Gerris  remigis,  water  skater,  187 
— Gelastocoris   oculatus,    toadbug,    269, 

271 
— Hydrometria,  marsh  strider,  187 
— Notonecta  undulala,    back  swimmer, 

187,  188 

— Ranatra  americana,    water   scorpion, 
104,  187,  239 


Hepatica,  Hepatica  triloba 

Hexagenia,  ]\Iay-fly,  289 

Honewort,  Cryptotaenia  canadensis 

Hornwort,  CeratophyUiim  demersum 

Hound's  tongue,  Cyanoglossum  officiniale 

Hudson  River  Valley,  18 

Hyacinth,  water,  Cammasia  escidenta 

Hydrophyte,  g^ 

Hydro  psyche,  caddis  fly,  286,  288 

H3'lodes  association.  150 

Hymenoptera,  Ants,  Bees,  Wasps: 

— Ammophila  proccra,  digger  wasp,  160 

— Bcmbex  spinolae,  digger  wasp,  no, 
"0,  154 

— Camptonotus  pennsyhanicus,  car- 
penter ant,  219,  227 

— Formoso  subpolitavar  neogagatcs,  ant, 
252 

— Las  ins  niger  americanus,  black  ant, 
158 

— Microbembex  monodonta,  digger  wasp, 
153,  154 

Ice,  II 

Igneous  rocks,  25 

lUinoian  glacial  period,  57,  62,  63 

Illinois  River,  8,  54 

lowan  glacial  period,  57,  63 

Iris,  Iris  versicolor 

Ischnura  verticalis  ponds,  179 

lyry,  poison,  Rhus  toxicode)idron 

Jack-in-the-pulpit,  Arisaema  triphyllum 
June  beetle,  95 

Karnes,  6y 

Kansan  Glacial  Period,  57 

Kaolin,  77 

Katydid,  see  Orthoptera 

Lady's-slipper,      \-ellow,     Cypripedium 
parviflorum 

Lake  Chicago,  62,  78,  80,  81,  85 

Lake  Michigan,  58,  59 

Lakeside,  10 

Lampsilis  luteolus  ponds,  179 

Lava,  18,  19 

Lead  plant,  Amorpha  canesccns 


INDEX 


321 


Leming,  Lapland,  298 
Lepidoplera,  Butterflies: 

— Angle  wings,  166,  230 

— Cosmopolitan,  230 

— Fritillary,  165,  230 

— Hair-streak,  Edward's,  166 

— Monarch,  165,  230 

— Mourning  cloak,  166 

— Nymph,  wood,  165,  224,  230 

— Painted  lady,  230 

■ — Red  Admiral,  166 

— Satyr,  wood,  166,  224 

— Swallowtail : 

giant,  Papilio  cresphontes,  222,  241 
pawpaw,  P.  ajax,  219,  221 
spice  bush,  P.  troilus,  166,  220,  221 
tiger,  P.  turnus,  222 

— Viceroy,  165,  230 

Lepidoptera,  Moths: 

— Actios  hma,  lunar  moth,  222 

• — Basilona  imperialism  imperial  moth, 

222 
— Calosoma  promethea,  promethea  moth, 

222 
— Catocala: 

amatrix,  sweetheart,  272 

neogama,  bride,  272 

retecta,     yellow-gray      underwing, 
222 

vidua,  widow,  222 
— Cither onia  regalis,  royal  moth,  222 
— Cressonia  jiiglandis,   walnut  sphinx, 

222 
—Diacrisia  virginica,  yellow  bear  moth, 

257, 258 

• — Estigmena  acraea,  salt-marsh  cater- 
pillar, 257,  258 

— Feltia  suhgothica,  dingy  cutworm 
moth,  257,  258 

— Isia  isahella,  Isabella  moth,  258 

— Prionoxystus  robiniae,  goat  moth,  226 

— Samia  cecropia,  cecropia  moth,  222, 
272 

— Scolecocampa  lihurna,  228 

— Telea  polyphemiis,  polyphemus  moth, 
222 

Lettuce,  wild,  Lactiica  scariola 

Light,  as  a  factor  in  plant  distribution, 
100,  109 

Light  intensity  in  forests,  202 

Lily-of-the-valley,  false,  Maianthemum 
canadensis 

Limestone,  45,  70 

Limonite,  72 


Lizard,  six-lined,  see  Reptilia 

Locust,  see  Orthoptera 

Loosestrife,    fringed,    Steironema    cili- 

atum 
Lousewort,  Pedicidaris  canadensis 

Lung  fish,  105 

Lupine,  Lupinus  perennis 

Luster,  70 

Magnesian  limestone,  34,  36,  47,  54 

Mammals: 

— Blarina     brevicaudata,      short-tailed 

shrew,  214,  274,  275 
— Citellus: 

franklini,  Franklin's  ground  squir- 
rel, gopher,  or  spermophile,  229, 

tridecemlineatns ,     thirteen-lined 
ground     squirrel,      gopher,      or 
spermophile,  252,  255 
— Condylura  cristata,  star-nosed  mole, 

252 
— Fiber  zibethicus,  muskrat,  241 
— Geomys  bursariiis,  pocket  gopher,  253, 

255 

— Marmota    monax,    woodchuck,    165, 

229,  230 

— Microtus: 

ochrogaster,  field  mouse,  253 
pennsylvanicus,      Pennsylvania 
meadov/  mouse,  253,  254,  256 

— Myotis  lucifugus,  brown  bat,  227 

— Peromycns: 

bairdii,  prairie  deer  mouse,  253  _ 
leucopus      novaboracensis,      white- 
footed  deer  mouse,  214,  217,  275 

— Scalopus  aquaticusy  mole,   165,   214, 

217,  275 

— Sciurus: 

caroUnensis  leticotis,  gray  squirrel, 
166 

hiidsonicus  loqiiax,  red  squirrel,  159 

niger  rufiventer,  fox  squirrel,  166 
— Sorex  personatus,  common  shrew,  229 
— Sylvilagus  floridaniis  mearnsii,  gray  or 

cottontail  rabbit,  229 
— Tamias    striatus    griscus,  chipmunk, 

159,  229 

— Zapus  hiidsonius,  jumping  mouse,  229 

Maple-beech  association,  115,  203,  206 
Maquoketa  shale,  see  Richmond  shale 
Marble,  dolomitic,  40 
Marsh  marigold,  Caltha  palnslris 
May  apple.  Podophyllum  pcltatum 


322       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


May-fly,  95;  nymph,  186,  239 
Meadow  rue,  Thalidrium  dasycarpum 
Meadow-sweet,  see  Shrubs 

Mermaid     weed,     false,     Proserpinaca 

palustris 
Mesophyte,  g6 
Mesozoic,  30,  31 
Meteorite,  23 
JMeteors,  23 
Mica,  71 

]Millipede,  see  Myriopoda 
Milfoil,  Myriophyllum  hcterophyllum 
]Milkweed,  Asdepias 
jMilkweed,  green,  Acerates  vi r id i flora 
Minerals,  68,  69;  table  of,  71-73 
Minooka  Ridge,  64 
Mint,  horse,  Monarda  punctata 
Mixed  oak  association,  115,  165 
Monadnock,  40 
Moons,  21 
Moon,  craters  of,  25 

Moraine:  ground,  <5j;  terminal,  19,  20, 

61,  62,  64,  65,  66;   Valparaiso,  78 
Morris  basin,  62,  66 
Mosquito  larvae,  104 
Moths,  see  Lepidoptcra 
Mount  Forest  Island,  64,  78,  83,  85,  86 
Mullein,  Verhasciim  Thapsus 
Myriopoda,  Centipedes  and  Millipedes: 

— Fontaria  corrugate,  218,  218 

— Geophilus  ruhens,  218 

— Lithohius,  224 

— Lysiopetalum  lactarium,  218 

— Polydesmus,  224 

— Spirobolus  marginatus,  218 

Nebula,  25 

New  Buffalo,  4 

Niagara  limestone,  t,t„  36,  38,  44,  47,  5'*^ 

North  America,  beginnings  of,  41 

Oak-hickory  association,  115,  221 

Odonata,  Damsel  flies: 

— Ischnura  verticalis,  177,  777 

— Lestes  Jorcipattis,  16 g,  169,  170,  lyo 

Odonata,  Dragon  flies: 

— Aeschna,  184,  281 
— Aeschnidae,  281 
— Agrionidae,  280 


— Anax  Junius,  184,  185,  239,  281 
— Boyeria,  184,  281 

— Calopterygidae,  280 

— Celcthemis  eponina,  i6q,  170 

— Cordidcgastcr     ohUquus,     lance-head 

dragon  fly,  269 
— Cordulcgastcridac,  281 
— Diastatomma,  281 
— Dromogomphus,  281 
— Epicordidia,  282 
— Gomp/iidae,  281 
— Gomphus  spicatus,  174,  174,  185,  239, 

282 
— Hagenius,  281 
— Leucorhinia  intacta,  iS;y,  185 
— Libellida  pidchclla,  185,  188,  239 
— Libellulidae,  281,  282 
— Macromia,  282 
— Progomphus,  281 
— Somatochlora,  28 j 
— Tetragoneuria,  283 
— Tramea  lacerta,  i6g 
Oceans,  origin  of,  27 
Olivine,  yj 

Onion,  wild,  Allium  cernuum 
Orchids: 

— Arethusa  hidhosa 
— Grass  pink,  Calopogon  pidchclliis 
— Ladies'-tresses,    Spiranthcs    Roman- 

zoffiana 
— Ragged,  Hahcnaria  lacera 
— Yellow  lady's-slipper,    Cypripedium 

parviflorum 

Ordoxdcian  period,  34,  38,  46,  48 

Orthoptera: 

— Ageneotettix    arenosiis,    sand    locust, 

157,  1 58 
— A  mblycorypha: 

oblongifolia,  oblong-wing  katydid, 
231,  241 

rotiuxdifolia,    round-wing    katydid, 
224,  231 
— Anoxipha  exigua,  small  brown  cricket, 

201 
— Ceiithophilus  maculatus,  camel  cricket, 

224,  225 
— Chloealtis  cons  per  sa,  sprinkled  locust, 

162,  163,  231 
— Conoccphalus: 

ensiger,  sword-bearing  grasshopper, 
163 

palustris,  marsh  conehead,  190,  192 
— Cyrtophillus    perspicillatus,    katydid, 

222 
— Diaphcromera      femorala,      common 

walking  stick,  166 


INDEX 


323 


Orlhoptcra — Continued 

— Dicromorpha     viridis,     short-winged 

green  locust,  190,  191,  ig2 
— Dissosteira  Carolina,  Carolina  locust, 

261 
— Hippiscus  iuberculatus,  coral-winged 

locust,  162,  163 
— Ischnoptera  pennsylvanica,  cockroach, 

218 
■ — Lcptysma       marginicolUs,       slender- 
bodied  locust,  190,  IQI 
- — M  ecostethuslmeatus  jStxiptdXocxxsl, 201 
— Melanoplus: 

angiistipennis,    narrow-winged    lo- 
cust, 157,  158 

atlanis,    lesser    migratory    locust, 

,j;57/ 157 

hmttatus,    two-lined    grasshopper, 

255,  256 
hlatchlcyi,  Blatchley's  locust,  219 
extremis,  northern  locust,  201 
femur-riibriim,    red-legged    locust, 

255,  256 
scudderi,  short-winged  locust,  2ji 
viridipes,  green-legged  locust,   219, 
256 
— Nemobiiis: 

fasciatus,   striped   ground   cricket, 

190,  192,  IQS 

palustris,  marsh  ground  cricket,  201 
— Oecanthus: 

angustipcfinis,    tree    cricket,    166, 
222,  231 

fasciatus,  222,  231 

latipennes,  222 

nivens,  222,  2ji 

quadripunctatus,  222 
— Orchelmiiim  vidgare,   meadow   grass- 
hopper, 256 
— Paratcttix  cnctdlatus,  hooded  grouse 

locust,  269,  271 
■ — Paroxya: 

hoos ieri,lioosieT\ocust,  190,  igi, ig2 

scudderi,  Scudder's  paroxya,   190, 

191,  ig2 

— Phaetaliotcs    nebrascensis,    Nebraska 
locust,  190,  192,  ipj 

— Psinidia  fenestralis,  long-horned  lo- 
cust, 156,  157,  15S 

— Schistocerca: 

aliUacea,  leather-colored  locust,  162, 

192,  193 

rubiginosa,  rusty  locust,  162 
— Scudderia: 

fur  cat  a,  forked-tailed  katydid,  224, 

243 

iexensis,  Texan*  katydid,  241,  243 


— Sparagemon  wyonmigianum,  mottled 

sand  locust,  156,  ij8 
— Stenobothrus  curtipennis,  short-winged 

brown  locust,  201 
— Telligidea: 

armata,  grouse  locust,  188 

granulatus,  190 

lateralis,  188,  190 

pdrvipennis,  188,  255 

pennata,  255 
— Trinierotropis     marilima,      maritime 

locust,  156,  156 
— Tryxalis  brevicornis,  igo,  191 
— Xiphidium: 

brevipenne,      short-winged      grass- 
hopper, 255,  256,  271 

ensiferum,    sworded    grasshopper, 
231 

fas  datum,  255 

nemorale,    woodland    grasshopper, 
231 

nigropleura,      black-sided      grass- 
hopper, 241 

strictum,      straight-lanced      grass- 
hopper, 163,  256 

saltans,  glade  grasshopper,  256 

Oxygen,  a  factor  in  distribution,  106 

Painted  cup,  Castilleja  coccinea 

Palaeozoic,  30,  31,  51 

Paleontology,  28 

Panne,  114,  115 

Parsnip : 

— Cow,  Heracleuni  lanatum 
— Wild,  Pastinaca  saliva 

Pea: 

— Beach,  Lathyrus  maritimus 
— Hoary,  Tephrosia  virginiana 

Pennsylvanian  period,  32,  38,  51,  54 

Peridote,  7s 

Phlox: 

— Hair}^,  Phlox  pilosa 
— Wood,  P.  divaricata 

Pigeon     berry,     see     Shrubs,     Corn  us 
canadensis 

Pigweed,    winged,   Cycloloma   atriplici- 
folium 

Pine  association,  115,  124 

Pitcher  plant,  Sarraccnia  purpurea 

Planarians,  291 

Planets,  21,  25 

Planetesimal  hypothesis,  22 


324 


A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Plankton,  food  of  fish,  109 

Platteville-Galena  limestone 

Polyzoan,  Pcdinella  magnifica,  240 

Ponds:  filling  of,  15,  16,  167,  232;  in 
dunes,  167,  179;  first  type,  168,  179; 
second  type,  182,  183;  third  type, 
179,  193,  194 

Ponds,  temporary,  life  of,  92 

Pondweed,  Potamogeton 

Porphyr}^  74 

Pot  holes,  86 

Potsdam  formation,  46,  47 

Prairie,  179,  242,  245 

Predatory  beetle  association,  150 

Preglacial  river  system,  58 

Proterozoic,  30,  31,  41 

Puccoon,  Lithospermum  canescens 

Pyrite,  72 

Pyroxene,  72 

Quarries,  36,  37,  45 

Quartz,  68,  69,  73 

Quartzite,  40 

Queen  Anne's  lace,  Daucus  Carota 

Rabbit,  wild,  see  Mammals 
Railroads,  routes  determined  by,  88 
Rain,  an  erosion  agent,  n,  27 
Rainfall,  effect  on  plant  distribution,  95, 

96,  97 
Rattlebox,  Crotalia  sagUtalis 
Rattlesnake   master,    Eryngium   yucci- 

folium 
Rattlesnake  root,  Prenanthes  alba 
Ra\dne:  clay,  4,  259;  formation  of,  3, 

5,  6,  261;  rock,  6,  7,  263 

Reptilia,  Snakes,  Turtles: 

— Aromochelys    odorata,    musk    turtle, 

178,  239 
— Aspidonectes     spinifer,      soft-shelled 

turtle,  23g 
— Chelydra  serpentina,  snapping  turtle, 

240 
— Chrysemus  marginaia,  painted  turtle, 

239,  240 
— Cnemidophorasexlineatiis,  sand  lizard, 

99,  160,  161 
— Coluber  constrictor,  blue  racer,  161 


— Grapfemys    geographicus,    geographic 
turtle,  23g 

— Hcterodon       platirhinos,       hog-nosed 
snake,  162 

— LeiopeUis  vernalis,  prairie  green  snake, 

25s 

— Thamnopkis     radix,     prairie     garter 
snake,  255 

Rice,  wild,  Zizania  aquatica 

Richmond  shale,  34,  38,  47,  52,  58 

Rivers,  action  of,  3,  27 

River  bottom  association,  271 

Rock:  dumps,  12 

Rocks,  68;  Chicago  region,  38,  43;  earh- 
ept,  25,  29,  39;  igneous,  73;  forma- 
tion, 17,  28,  44;  metamorphic,  39, 
40,  76;  Plutonic,  7^;  sedimentary, 
17,  28,  29,  70;  systems  of,  31,  38; 
table  of,  75;   volcanic,  73 

Rock  River,  6,  54 

Rosin  weed,  Silphium  terebinthinaceum 

Rotifers,  288 

Rotting  log  association,  225 

Rush,  bog,  J  uncus,  several  species 

Rush,  spike,  Eleocharis  acicularis 

Sag  Station,  8,  78 

St.  John's-wort,  Hypericum  Kalmianum 

St.  Peter's  sandstone,  34,  38,  46,  54 

Salt  Creek,  3,  4,  83 

Sandbars,  113 

Sarsaparilla,  Aralia  niidicaulis 

Sawfly,  257 

Saxifrage,  swamp,  Saxifraga  penn- 
sylvanica 

Schist,  4.0,  76 

Sea  rocket,  Cakile  edentula 

Seas,  epicontinental,  44 

Seasonal    distribution    of    plants,    92, 

248 

Sedges,  see  Carex 
Sedimentation,  28 
Serpentine,  71 
Shale,  46,  76 


INDEX 


325 


Shrubs : 

— Andromeda  poll/ alia,  ig8,  199 

— Arctostaphylos    Uva-ursi,    bearberry, 

124,  125,  727  . 

— Benzoin  aestivalis,   spice  bush,    205, 

207,  221 
— Betula  pumila,  swamp  birch,  igg 
— Cephalanthus      occidentalis,      button 

bush,  177,  179,  241,  274 
— Chamaedaphne  calyculata,  leatherleaf, 

198,  199,  200 
— Chimaphila  nmhellata,  Prince's  pine, 

124,  126,  128 
• — Cornus: 

alkrnifolia,    alternate-leaved    dog- 
wood, 228 

Amomum,  silky  dogwood,  241 

canadensis,  pigeon  berry,  205,  209 

paniculata,  panicled  dogwood,  228, 
264 

stolonifera,  red-osier  dogwood,  122, 
123,  124,  183,  200,  241,  260 
— Diervilla  Lonicera,  bush  honeysuckle, 

132,  133,  134 

— Dirca  palustriSjlesLtherwood,  205,  2og 
— Evonymus: 

americana,  strawberry  bush,   205, 

208,  2og,  274 
atropurpiireiis,   wahoo  or  burning 
bush,  205,  207,  208,  274 
— Gaidtheria  procumbens,  checkerberry, 

124,  126,  128,  180,  205 
— Gayliissacia  haccata,  huckleberry,  132, 

133,  134,  264  _ 

— Hamamelis    virginiana,    witch-hazel, 

205,  206,  207,  221,  228,  270 
— Hydrangea  arhorescens,  265,  267 
— Ilex  verticillata,   swamp   holly,    180, 

181,  181 
— Juniperus: 

communis,   common  juniper,    124, 
i2y 

horizontalis,  prostrate  juniper,  114, 
121,  124,  127 
— Physocarpus     opidifoliiis,     ninebark, 

264 
— Primus  pumila,  sand  cherry,  1 19, 120, 

121 
— Pyrola  elliptica,  shinleaf,  124, 126,  128 
— Pyrus   arbutifolia,   chokeberry,    198, 

199 
— Rhus: 

canadensis,  aromatic  sumac,   124, 

130,  131 
copallina,  dwarf  sumac,  1 24,  130, 

131 

glabra,  smooth  sumac,  228,  264 


typhina,  staghorn  sumac,  124,  130, 

131,  228,  260,  264 
vernix,   poison    sumac,    130,    131, 
200 
— Ribcs: 

floridum,  black  currant,  205 
Cynosbati,  prickly  gooseberry,  205 
— Rosa  acicidaris,  I2g 
blanda,  i2g 
humilis,  I2g 
virginiana,  200 
— Salix: 

glaucophylla,  broad-leaved  willow, 

120,  260 
syrticola,  furrvMvillow,  119, 120,  122 
— Sarjibucus  canadensis,  elderberry,  205, 

208,  2og,  274 
— Spirea: 

latifolia,  meadow-sweet,  180,  181, 

181 
tomentosa,   steeplebush,    180,    181, 
181 
— Staphylea  trifolia,   bladdernut,    273, 

274 
— Vaccinum: 

macrocarpon,  large  cranberry,  198 
pennsylvanicum,     blueberry,     132, 

264 
oxycoccos,  small  cranberr}',  198 
— Viburnum: 

acerifolium,    maple-leaved    vibur- 
num, 205,  20J,  241 
lentago,  nannyberry,  205,  20 j,  208, 

228 
opulus,  high  bush  cranberry,  205, 
207,  208 
— Zanthoxylum     americanum,     prickl\" 
ash,  241,  273,  274 

Shooting  star,  Dodecatheon  meadia 
Shooting  star,  see  Meteor 
Silurian  period,  2)2>,  Z^,  47,  48 
Siphlurus  alter natus,  May-fly  n\mph, 
287 

Skokie  Bay,  81 

Skokie  Marsh,  81 

Skunk    cabbage,    Symplocarpus   focti- 

dus 
Skull  cap,  Scutellaria  galcriculata 
Slate,  40 
Slugs: 

— Agriolimax  campcstris,  217,  21S 
— Pall  if  era  dors  alls,  21S  . 
— Pliilomycus  carol  incus  is,  216,  21S 
Smart  weed,  Polygonum 


326       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Snails,  aquatic: 
— Amnicola: 

cinclnnatiensis,  175,  176,  233 

emarginata,  233 

limosa,  175,  iy6 
— Ancyhis  fuscus,  233,  288 
— Campcloma: 

integrum,  233,  289 

ponder 0 sum,  233 

suhsolidiim,  233,  289 
— Goniohasis  livescens,  232,  233,  288 
— Lymnaea: 

desidiosa,  176,  177 

humilis,  176 

rejiexa,  176,  188,  233 

stagnalis,  233 

woodrujji,  233 
— Physa: 

gyrina,  175 

heterostropha,  233 
— Planorhis: 

hicarinatus,  176,  177,  233 

campamdatus,  176,  J77,  188,  233 

hirsiitus,  176,  777 

parvus,  176,  777,  188 

trivolvis,  233 
— Pleurocera: 

elevatum,  232,  233 

subulare,  232,  233 
—  Valvata  tricarinata,  233 
— Vivipara: 

contectoides,  232,  233 

suhpurpurea,  233 

Snails,  terrestrial: 

— Bifidaria  armifera,  216 

— Circinaria  concava,  214,  216,  227,  269, 

270 
— Cochliocopa  luhrica,  216 
— Helicodiscus  parallelus,  216 
— Omphalina: 

friabilis,  214,  217,  270 

fidiginosa,  214,  216,  2/7,  227,  270 
— Polygyra: 

albolabriSf  214,  215,  217,  226,  269, 
270 

clansa,  217,  270 

fraudulenta,  214 

fraterna,  270 

hirsuta,  214,  215 

inflecta,  270 

monodon,  214^  216,  270 

muUilineatus ,  215,  217,  270 

oppressa,  214,  270 

palliatay  214,  215,  270 

pennsyhanica,  215,  277,  270 

profioida,  165,  215,  277 


thyroides,  215,  277,  226,  269,  270 

tridentata,  215,  216 
— Pyramidida: 

alternata,  214,  216,  277,  227,  269, 
270 

perspectiva,  214,  216,  277,  227,  270 

solitaria,  214,  216,  277,  269,  270 

striatella,  217 
— Succlnea: 

avara,  216,  272 

ovalis,  216,  272 

retusa,  216,  272 
— Vertigo  ovata,  216 
— Zonitoides   arboreus,    165,    214,    216, 

277,  227,  270 

Snake,  jee  Reptilia 

Soil  formation,  27 

Solomon's  seal,  Polygonatum  biflorum; 
false,  Smilacina  racemosa 

Sowbug,  218 

Sphaeridae,  184 

Sphagnum  moss,  194,  195 

Sphalerite,  72 

Spiders,  5ee  Arachnida 

Spiderwort,  Tradescantia  virginica 

Sporebearers  (^ee  a/^o  Ferns) : 

— Chara,  168,  172,  772,  178,  196 
— Cladophora,  234 
— Conocephalus,  265 
— Equisetum: 

arvensis,  260 

fluviatile,  195,  198,  248 

hyemale,  122,  260,  261 
— Hydrodidon,  234 
— Marchantia,  265 
— Oedogonium,  234 
— Riccia,  234 
— Ricciocarpus,  234 
— Selaginella  rupestris,  265 
— Sphagnum,  moss,  234 

Spring  beauty,  Claytonia  virginica 

Spring  flora,  92 

Spurge: 

— Flowering,  Euphorbia  corollata 
— Seaside,  E.  polygonifolia 

Squirrel,  see  IMammals 

Star  flower,  Trientalis  americana 

Star,  new,  22 

Stars:      morning     and     evening,     21; 
number  of,  21,  22 

Starved  Rock,  7,  8,  9 


INDEX 


327 


Stone  fly,  larva,  186 

Stony  Island,  36,  85,  87 

Streak,  70 

Stream:    action   of,   3;     communities, 
276,  277,  278 

Sugar  Creek,  10 

Sun,  21;  rate  of  movement  of,  22 

Sundew,  Drosera  rotundifolia 

Sweet  Cicely,  see  Cicely 

Syenite,  75 

Talus,  12 

Tamarack-sphagnum  bog,  179,  193,  194 

Tamarack  zone,  200 

Tape  grass,  Vallisneria 

Temperature,  effect  of,  on  plant  and 
animal  distribution,  90 

Termites,  Termes  flavipes,  152 

Tiger  beetle,  distribution  of,  148 

Thimbleweed,  Anemone  cylindrica 

Thistle: 

— Bull,  Cirsium  lanceolatum 
— Canada,  C.  arvense 
— Pasture  or  prairie,  C.  pumilum 
— Sand,  C.  Pitcherii 

Thorn  Creek,  2,  4 

Tickseed,  Coreopsis  grandi flora 

Toadflax,  bastard,  Comatidra  umbellaia 

Toad:  life-history  of,  102;  see  Amphibia 

Tolleston  stage  of  Lake  Chicago,  84,  87 

Tooth  wort,  Dentaria  laciniata 

Touch-me-not,  Impatiens  biflora 

Trees: 

— Acer: 

saccharinum,     river-bank     maple, 
272,  274 

sacchariim,    hard,   rock,   or   sugar 
maple,  205,  206 
— Amelanchier   canadensis,   Juneberry, 

shadbush,   sugar  plum,   132,   133, 

205 
— Asimina  triloba,  pawpaw,  20^,  208, 

274 
— Betula  alba,  white  birch,  260 
— Carpinns'  caroliniana,   water   beech, 

137,  138,  140,  205,  206,  270 
— Celtis    occidentalis,    hackberry,    203, 

204,  204 
— Cercis  canadensis,  red-bud,  205,  206, 

208,  274 


— Cornus  florida,    flowering  dogwood, 

205,  206,  207,  274 
— Crategns,  hawthorne,  228 
— Fagiis  grandifolia,  beech,  204 
— Fraxinns: 

americana,  white  ash,  272,  274 

nigra,  black  ash,  272,  274 

pcnnsylvanica,  red  ash,  272 

quadrangulata,  blue  ash,  272,  274 
— Gymnocladus  dioecia,  Kentucky  coffee 

tree,  271,  274 
— Juglans: 

cinerea,   white   walnut,    203,    204, 
221,  274 

7iigra,  black  walnut,  203,  204,  221 
— Juniper  us  virginiana,  red  cedar,  124, 

127,  260 
— Larix  laricina,  larch,  tamarack,  193, 

200 
— Lirode'udron    Tulipifera,    tuhp    tree, 

203,  203,  274 

— Nyssa  sylvatica,  sour  gum,  178,  180 

— Ostrya  virginiana,  hop  hornbeam,  137, 
138,  205,  206,  270 

— Finns: 

Banksiana,  jack  pine,  124,  12/,  260 
strobus,  white  pine,  7,  124,  i2y,  260 

— Platanus  occidentalis,  sycamore,  203, 

204,  205,  274 
— Populus: 

deltoides,    cottonwood,    114,    116, 

120,  122,  260 
gra}ididentata,  large-toothed  aspen 

228,  260 
tremoloidcs,    small-toothed    aspen 

228,  260 
— Pruniis: 

nigra,  wild  plum,  228 
pennsylvanica,  pincherry,  132,  133 
serotina,  black  cherr}',  203, 204, 204, 

221,  274 
virginiana,  choke  cherr}',  132,  133, 

264,  265 
— Ptelea  trifoliata,  hop  tree,  132,  134, 

270 
— Pyrus  coronaria,  wild  crabapple,  22S> 
— Quercus: 

alba,  white  oak,  137,  138,  139 
bicolor,  swamp  white  oak,  139 
coccinca,  scarlet  oak,  139 
cllipsoidalis,  northern    pin    or   hill 

oak,  139 
imbricaria,  shingle  oak,  139 
macrocarpa,  bur  oak,  139 
mariltindica,  blackjack  oak,  139 
Mic/iaiixii,  basket  oak,  139 


328       A  NATURALIST  IN  THE  GREAT  LAKES  REGION 


Trees — Continued 

Miihlenbergii,  cinquapin  or  chest- 
nut oak,  132,  137,  139 
paliistris,  pin  or  swamp  oak,  139 
rubra,  red  oak,  137,  138,  139 
velutina,  black  oak,  132,  137,  139, 
264 
— Salix: 

longifolia,  272 
luctda,  shiny  willow,  183 
nigra,  272 
— Sassafras  variifolium,  131,  132 
— Thuja  occidentalis,  arbor  vitae,  124, 

126,  i2y 
— Tilia  americana,  linden  or  basswood, 

137,  138,  221,  274 
— Uhniis: 

a wmcawa,  white  elm,  138,  203,  205, 

272 
fulva,  red  or  slippery  elm,  137,  203, 
272 
Trillium,  Trillium  gra^idifloriim;    T.  re- 

curvatum 
Turtle,  see  Reptilia 

Unglaciated  region,  60 
Upheaval  of  rock  beds,  17,  18 

Valley:  drowned,  18;   formation,  4,  5, 

7,  8,  9- 
Valley  trains,  20,  64,  66,  67,  87 

Vines: 

— Celastrus  scandens,  bittersweet,  122, 

124,  130,  131,  274 
— Lonicera  Sullivantii,  honeysuckle,  274 
— Menispermiim  canadense,  moonseed, 

273,274 
— Psedera  quinqucfolia,  woodbine,  124, 

130,  274 

— Rhus  Toxicodendron,  poison  ivy,  124, 

131,  132,  274 

— Smilax  hispida,  272,  273 

— Vitis: 

aestivalis,  summer  grape,  130,  131 
cordifolia,  frost  grape,  130,  131 
mdpinus,    river-bank    grape,    130, 
131,  274 

Violet : 

— Arrow-leaved,  Viola  sagitlata 
— Birdfoot,  V.  pedata 


— Canada,  V.  canadensis 

— Dogtooth,  Erythronium  americanum 

— Long-spurred,  V.  rostrata 

— White,  V.  blanda 

— Wood,  V.  palmata 

Virginia  creeper,  see  Vines 

Volcanoes,  18 

Warren's  Woods,  205 

Water  as  a  factor  in  plant  and  animal 
distribution,  95 

Water  boatman,  see  Hemiptera 

Water  breathers,  loi,  102 

Water    buttercup,     Ranunculus    aqua- 
tilis 

Waterleaf,  Hydrophyllum  virginianum 

Water  lily : 

— Yellow,  Nymphaea  advena 
— White,  Castalia  tuber os a 

Water    mite,    Limnochares    aqualicus., 

175 
Water  penny,  Psphenus  lecontei,    287, 

288 

Water  scavenger,  187 

Water  scorpion,  see  Hemiptera 

Water  shield,  Brasenia  Schreberi 

Water  sowbug,  Asellus 

Water  tiger,  186 

Wave  action,  2,  3,  27 

Waves,  force  of,  3 

Weathering,  27 

Weevil,  see  Coleoptera 

White  ants,  152 

Wild  ginger,  Asarum  canadense 

Willow  Springs,  13,  36,  64 

Wind,  erosion  agent,  13 

Wintergreen,  see  Checkerberry 

Wisconsin  Glacial  Period,  57,  63,  79 

Wormwood,  Artemisia  caudata 

Xerophyte,  g6 
Xerophytic  adaptations,  98 

Zonation  of  life,  90 


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1^  C*  State  College 


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